So Saturday's final will be Serena Williams v Lucie Safarova.
Safarova will have to overturn a 8-0 losing record against Williams if she is to lay her mitts on her first Grand Slam title. But with Williams in such unpredictably out of sorts form you never know.
See you here for that and possibly the small matter of the men's semi-finals tomorrow. Ciao for now.
Post update
The drama was in the detail, but let's have a look at the stats behind that see-sawing merry-go-round of a match.
Williams-Bacsinszky
Aces: 8-4
First serve %: 57-70
Double faults: 0-3
% pts won on first serve: 78-60
% pts won on second serve: 47-30
Winners: 37-26
Unforced errors: 30-24
Post update
The television cameras follows Serena Wiliams back into the bowels of Philippe Chatrier, capturing her reunion with coach and partner Patrick Mouratoglou.
Williams is too shattered to lift her arms to hug the Frenchman. She looks out on her feet. As she has for the whole of the match.
Mouratoglou points the way to somewhere out of shot - possibly the medicine cabinet.
Williams through to final
Williams 4-6 6-3 6-0 Bacsinszky
Piers Newbery
BBC Sport at Roland Garros
"It was Williams who began the match close to tears, it's Bacsinszky who leaves the court in floods. She had looked on course for a first major final but Williams somehow managed to hit back from a set down for the fourth time this tournament - the first time she has done that at a Grand Slam. Coach Patrick Mouratoglou gives her a hug backstage and then guides her gingerly down the stairs away from the cameras."
Get involved
via text on 81111
Rebecca: Serena is a genius. Her antics have kept the crowd sympathetic to her. Otherwise they would have been cheering for the Swiss player.
Anuj, Harrow: All the Serena critics should show some more respect. This is the greatest female player of all time! Why would she need to fake an illness to gain an advantage?
Martin H, Coventry: Suspect that Serena will be picking up the trophy on Saturday in Paris and an Oscar in Hollywood later in the year.
Post update
Serena Williams: "I don't know how I did it. If I was going to lose, I didn't want to lose without a fight. I just tried to find some energy form somewhere. I hope I will get better before Saturday. I am ill."
Williams through to final
Williams 4-6 6-3 6-0 Bacsinszky
Getty ImagesCopyright: Getty Images
Well, that was a hard day at the office.
One extraordinary cross-court pass, from well out wide and a split legged sliding stance, was the sort of thing that Williams would be proud of at full fitness.
She sways and staggers to her chair after getting some sincere and sporting congratulations from Timea Bacsinszky.
Bacsinszky is strugging to hold back tears. So is Williams. Not a dry eye on the court.
Williams breaks
*Williams 4-6 6-3 5-0 Bacsinszky
EPACopyright: EPA
Timea Bacsinszky has come off the boil certainly, but Serena Williams is just slinging pure power off either wing.
She crashes away a forehand on the first of two break points at 15-40.
Off she slopes towards the changeover chair. Twenty-seven minutes on the clock for this set and a lot of that has been taken up by Williams's go-slow between points.
Post update
Williams 4-6 6-3 4-0 Bacsinszky*
EPACopyright: EPA
Heaving shoulders, hacking cough and Serena Williams is still ill.
Simon Briggs diagnoses bronchitis from the BBC Radio 5 live sports extra commentary box. But the form and prospects are looking increasing perky.
The American holds to 15 and a hotel room bed and honey and lemon drink might not be far off.
Post update
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
"Lucie Safarova will be happy with what she's seeing at the moment. She's got a wounded animal on one side of the net and a psychologically-damaged player on the other."
Post update
Piers Newbery
BBC Sport at Roland Garros
"The momentum might have shifted dramatically on court but there's not much change off it, with Williams taking on the biggest ice towel of the day and leaning her head in her hand during the two-minute break. Bacsinszky looks unperturbed as she takes on water, perhaps resigned to the inevitable?"
Get involved
via text on 81111
Rose, Oxford: What a surprise. Back she comes. I feel sorry for who ever she plays. Not very sportsmenlike.
Get involved
#bbctennis
Curtis: Bacsinszky's forehand is pretty much non-existent, no wonder Serena is peppering it now, easy third set for Serena.
Ayo Obit: Problem is Timea is primarily a counter-puncher and Serena, even a half-fit Serena, does NOT lose to counter-punchers!
Williams breaks
*Williams 4-6 6-3 3-0 Bacsinszky
EPACopyright: EPA
Curtains? I fear it might be.
Timea Bacsinszky skirts around a couple of break points as Serena Williams plops long on the backhand.
But she plummets a double-break behind on a third as he strays beyond the baseline.
Post update
Williams 4-6 6-3 2-0 Bacsinszky*
Serena Williams hammers away a backhand punch and hollers to the skies as she backs up the break.
You could say that Timea Bacsinszky had her chances at 15-40. But are they really chances when you get two serves fizzed around your lugholes on both break points?
Williams's coach Patrick Mouratoglou is earning his corn today. He is out of his seat, clenching teeth, fist and anything else he has got in celebration. He'll give himself a hernia doing that.
Get involved
via text on 81111
Jaime, Huntingdon: Personally I suspect Serena enjoys the added attention she gets when she wins while being "unwell". All too common I'm afraid. Perhaps being so dominant makes such self-indulgence possible.
APCopyright: AP
Williams breaks
*Williams 4-6 6-3 1-0 Bacsinszky
That is kamikaze tennis from Timea Bacsinszky.
From 30-0 down, Serena Williams lands a whopping roundhouse inside-out forehand on return to move to 30-30.
No need for panic. Plenty of margin for error.
But Bacsinszky loses her composure quite dramatically, cracking two inviting mid-court dollies, bouncing high and gentle for her to put away, outside the lines.
Williams with a freebie of a break.
Get involved
via text on 81111
John Head, London: Serena is always most vicious when up against it. Memories of Australian Open quarter-final (2010) with Azarenka coming to the fore. She was 6-4 4-0 down in that one, I'd imagine this is not cause for concern to her.
Getty ImagesCopyright: Getty Images
Post update
Williams 4-6 6-3 Bacsinszky*
Out they come for the third...
Serena Williams is still not raising her pace above octogenarian levels if there is not a live tennis ball to chase.
Get involved
#bbctennis
RieruM: If there's one thing I've learned from Roland Garros 2015, is that if Serena loses the first set it doesn't mean much!
Michael S: Serena to make a miraculous recovery and win the third set 6-0?
"Sheer bloody-mindedness, sheer brilliance, from Serena Williams when she is clearly not 100%. We are going the distance."
Getty ImagesCopyright: Getty Images
Williams wins the second set
Williams 4-6 6-3 Bacsinszky*
Serena Williams racks up two set points at 40-15.
Timea Bacsinszky shoots them down.
But Williams rolls out the heavy artillery, booming down a bazooka ace to set up a third that proves the charm. Into a decider.
Serena with the momentum or Timea without the illness? Let's find out.
Williams breaks
*Williams 4-6 5-3 Bacsinszky
Coach Patrick Mouratoglou leads the cheer squad as Serena Williams sniffs blood, advances and slaps away the forehand drive volley at break point and 30-40.
Timea Bacsinszky is being pulled out of shape by the top seed's power when the rallies are allowed to develop.
She doesn't seem able to destabilise Williams, or force her into lateral movement, as she did in the first set.
Getty ImagesCopyright: Getty Images
Get involved
#bbctennis
David Jack: People making ludicrous claims that Williams is faking her illness. Yeah, cos that's a brilliant tactic isn't it.
PS: Sick of Williams' antics which have been fairly consistent last few years.
Getty ImagesCopyright: Getty Images
Post update
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
"Tactically it is quite a dilemma for Bacsinszky. It is always an awkward scenario when your opponent is struggling. The dilemma is that you try to work them around the court, get them running and losing more energy, but then you can lose your own game."
Post update
Williams 4-6 4-3 Bacsinszky*
Serena Williams may only be operating in second gear, but she is red-lining it all the way in the shots that he does hit.
Successive crackerjack aces down the middle seal the game and save the American from having to expend any more energy then she has to.
She is ahead on the scoreboard again. A crucial time in the match now. The last thing that Bacsinszky should do is give her opponent the tonic of a break.
EPACopyright: EPA
Get involved
#bbctennis
Nick Powell: Can't tell if Serena is faking or not, I suspect not, but how many times have we seen her in this state before dominating.
Williams breaks
*Williams 4-6 3-3 Bacsinszky
Deary me.
Timea Bacsinszky has been all-out attack so far in the match and it has served her well.
But the purple patch fades slightly as the Swiss boshes down the line and out to allow Serena Williams to 15-40 and two break points.
She converts the first as Bacsinszky fails to crowbar a backhand off the dust.
Getty ImagesCopyright: Getty Images
Post update
Piers Newbery
BBC Sport at Roland Garros
"While Bacsinszky holds up a deflated ball to the umpire at the changeover, her opponent is looking similarly beaten on the opposite chair. Williams cannot sit up straight and is coughing and spluttering, looking tearful once again."
Post update
Just in reply to Philip in the tweet below, I don't think that anyone thinks that Serena Williams is faking an illness.
It is just the way she seems to be coping with it is to act out every cough, splutter and ache in triplicate.
There is more swooning and swaying at the changeover.
"I still think there's plenty of mileage left in this match - but it is getting very, very tight for Williams."
Bacsinszky breaks
Williams 4-6 2-3 Bacsinszky*
Timea Bacsinszky is all over the Serena Williams serve like a an angry rash.
Two break points have already disappeared down the swanny, when the Swiss breaks out a drop-shot return winner to Serena Williams' rocket. Extraordinary.
Williams sees off another two break points but finally at the sixth time of asking, Bacsinszky has the break as Williams cuffs a backhand wide.
Get involved
#bbctennis
Philip Farrell: Come on guys, two text messages implying Serena is faking it seems a bit harsh. She doesn't look well.
APCopyright: AP
Post update
*Williams 4-6 2-2 Bacsinszky
One forehand error and three off the backhand seal Serena Williams's demise to love.
Plenty of pop in Timea Bacsinszky's groundstrokes to force those mistakes, but it looks like Williams has suffered a set-back.
There has been more twists and turns in her performance - and dare I say it hammy acting - than a Brazilian telenovela.
Post update
Williams 4-6 2-1 Bacsinszky*
Maybe there was a swig of WD40 amid all the isotonic.
Serena Williams looks like she is moving a little more freely suddenly, Her foot movement is busier, her forehand arm is swinging easier and she holds her serve with relative ease.
Have we started the upturn of the Williams U-turn in this match?
Getty ImagesCopyright: Getty Images
Get involved
via text on 81111
Chris, London: Amazing how Serena can look like she will collapse in between points and yet still the ball as hard as always during the point.
Post update
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
"Serena is making a lot of hand gestures - 'all is against me,' she says. 'Even the gods are smiling on my opponent.' It would be an amazing comeback from Serena considering all the spluttering and almost fainting she is doing. Assuming she is not exaggerating her illness, it would be remarkable to get out of this position."
Getty ImagesCopyright: Getty Images
Post update
*Williams 4-6 1-1 Bacsinszky
Serena Williams looks exasperated as a Timea Bacsinszky forehand snags the wire looping up, over her shoulder and in to seal the game for the Swiss.
I think that Williams is playing this match to an internal soundtrack of sobbing violins. Everything is against her.
If and when she stops feeling sorry for herself and starts to fight back against whatever is afflicting her, she has a chance.
Get involved
via text on 81111
John, London: Granted, Serena Williams doesn't look well - but seems like she's employing the old tactic of 'Laying it on thick' - cue miraculous recovery.
Get involved
#bbctennis
Mark Johncock: I may be cynical but what are the odds of Serena suddenly feeling better if she manages to get ahead in second set?
Safarova reaches final
Ivanovic 5-7 5-7 Safarova
Roland Garros/TwitterCopyright: Roland Garros/Twitter
French Open finalist Lucie Safarova in her post-match news conference: "It's slowly sinking in that I've reached the final...the happiness is unreal!
On closing out the semi-final win: "I think when I finally realised I could be in the final I was overthinking."
Post update
Williams 4-6 1-0 Bacsinszky*
Do you remember Serena Williams having to withdraw from the doubles event at Wimbledon last year because of a virus?
"How on Earth did Bacsinskzy stay in that point? Wonderful defending, almost Andy Murrayesque, making her opponent make one more shot when Serena looked like she had the point won two or three times. Then she was made to play the extra shot and missed. Incredible."
Bacsinsky wins first set
*Williams 4-6 Bacsinszky
Lukas Rosol, Steve Darcis, Sergiy Stakhovsky.
I reckon that Timea Bacsinszky could be about to join an elite band of giant-killers.
The Swiss shows no mercy, forcing an apparently suffering Serena Williams into shuttle runs at the back of the court to defend set point at 40-15.
Williams takes on the role of line judge, calling a Bacsinszky groundstroke long and convincing the umpire of her case as she clambers out of her high chair for a better look.
A rolling forehand across court saves the second set point for Williams, but Bacsinszky shows that she has stomach for the fight, blasting away a corking forehand to set up a third from deuce.
ReutersCopyright: Reuters
Post update
Piers Newbery
BBC Sport at Roland Garros
"Williams wraps herself in towels at the changeover and asks the umpire, 'That's not the set is it? Because they're sweeping the lines.' She then buries her head in an ice towel, and takes a glug of water.
"The world number one is in real trouble; hard to see how she finishes this match, let alone as the winner."
"Serena often walks slowly around the court in the early stages of matches, but she is clearly struggling - no doubt about it. Now she is wrapping an ice towel around her forehead. If you've got a headache and then are playing sport in 28C heat, it is not a pleasant place to be."
Post update
Williams 4-5 Bacsinszky*
Serena Williams is struggling here.
She has held to 30, but the story is not the scoreboard.
The American looks to be on the point of tears, mopping her brow between points, blinking as she stares downcourt, and hobbling to her seat at the changeover.
If she is playing possum to try and lure Bacsinszky into a false sense of security, it is an Oscar winning performance.
Bacsinszky to serve for the opening set.
Safarova reaches final
Ivanovic 5-7 5-7 Safarova
Beaten semi-finalist Ana Ivanovic in her post-match news conference: "I'm really proud of what I achieved in these two weeks. I'm aware that there's still room for improvement and that is the exciting part."
Post update
BBCCopyright: BBC
Post update
*Williams 3-5 Bacsinszky
Timea Bacsinszky is showing no signs of stuttering or faltering.
The Swiss gets a chunky slice of luck with a thick netcord that bounces her way, but there was nothing streaky about the rest of the game.
Get involved
#bbctennis
Bernie Austin: I like what Bacsinszky is doing so far Serena needs her A game quickly! Can she maintain this level?
Post update
Williams 3-4 Bacsinszky*
Serena Williams bellows a "C'mon" down court after bashing away a backhand. That was directed at herself as much as Timea Bacsinszky or her camp.
Getty ImagesCopyright: Getty Images
She is trying to rev herself up. Will it take the loss of the first set to jump-start her game? Or is not going to be able to fight off whatever is ailing her as well as Bacsinszky?
American journalist, and 5 live sports extra co-commentator, Courtney Nguyen: "Bacsinszky is completely outplaying Serena so far. We know Serena's quality but Bacsinszky is doing what so many fail to do when under pressure against the American - that is getting on top of the things given by Serena. She is keeping Serena running and on the defensive."
Post update
*Williams 2-4 Bacsinszky
That won't make Serena feel any better.
Timea Bacsinszky is showing some very unSwiss aggression, snarling at anything short and walloping winners.
A hold to consolidate the break and clear blue water between her and the world number one.
Getty ImagesCopyright: Getty Images
Post update
Good call Ali.
Williams was clutching a towel to her forehead and had ice packs round her neck during the changeover, doing her best impression of an Austin-era debutante with a fit of the vapours.
Intriguing.
Get involved
#bbctennis
Ali: Can't get used to Serena's body language between points. She looks uninterested! Injured? Unwell? Poker face?
American journalist, and 5 live sports extra co-commentator, Courtney Nguyen: "Serena Williams doesn't give you much but whatever she has given Bacsinszky has taken. It has been a perfect start for Bacsinszky, she has managed to shrink the court a little bit and show Serena that she has to deliver that little bit more to get past her.
Getty ImagesCopyright: Getty Images
"Bacsinszky is clear in her mind and is clear in her game plan. What a return to gain that break!"
Bacsinszky breaks
*Williams 2-3 Bacsinszky
Timea Bacsinszky works up a break point at 30-40, but, even under the weather, Serena Williams has that serve to cling to.
One right up on the apex of the service box knocks Bacsinszky back a step. But the Swiss is not to be denied.
A rasping return winner from the underdog earns a pat of applause from Wiliams, a glorious backhand lob earns another bite at the break cherry and a crunching return sends her back to her stool ahead on the scoreboard for the first time.
Post update
Williams 2-2 Bacsinszky*
Nice!
Timea Bacsinszky bops a forehand down the line, before closing out the game with a spicy ace.
Serena Williams has been a slow starter in previous rounds this fortnight and she is not chasing too hard.
"Get on the balls of your feet." Is probably what coach Patrick Mouratoglou is shouting from the players box.
Getty ImagesCopyright: Getty Images
The heat is on
Williams 2-1 Bacsinszky*
Piers Newbery
BBC Sport at Roland Garros
"Bacsinszky might hail from Lausanne but she could relish the toasty conditions on Chatrier today after enjoying the best run of her career in Mexico earlier this year. The Swiss won 10 matches in a row as she took the titles in Acapulco and Monterrey. The unofficial (my phone) temperature of 26C would not normally trouble Florida-resident Serena, but she has felt unwell throughout the tournament."
Murray watch
Getty ImagesCopyright: Getty Images
News from Roland Garros ground control...
Andy Murray has been assigned second use of Court Philippe Chatrier tomorrow for his semi-final against Novak Djokovic.
Fair enough. It is a match that demands headline billing.
However it means that we have no definite start time.
Murray will be on court once Jo Wilfried Tsonga and Stan Wawrinka - who start at 12:00 BST - are finished in the other last-four match.
Tsonga and Wawrinka have broken through the four-and-half-hour barrier in their previous two meetings at Roland Garros.
A traditional Friday early knock-off and you might be back from work in time for the meat of the match.
Sarafova reaches final
Ivanovic 5-7 5-7 Safarova
TwitterCopyright: Twitter
Post update
Williams 2-1 Bacsinszky*
Ominous.
Serena Williams bruises down four beefy serves as Timea Bacsinszky feels the top seed's full force.
It is like sticking your head out of the window of the Tokyo-Kyoto express train facing the Williams' serve.
Post update
*Williams 1-1 Bacsinszky
Ooh la la.
Timea Bacsinszky produces a beautifully controlled drop volley that is far out of the reach of the onrushing Serena Williams. That stops the rot at 0-30. It was so good that Marion Bartoli - on commentary for British television - couldn't help herself from reverting back to her mother tongue in her delight.
Bien joué indeed.
Bacsinszky does decently from deuce as well, stuffing away a second serve down the middle when Williams was sniffing around like a bloodhound.
A good hold. But how much variation can the Swiss bring to her serve to keep it out of reach?
APCopyright: AP
Post update
Williams 1-0 Bacsinszky*
Take those lazy stereotypes about French time-keeping and efficiency and shove them in the shredder.
We are out and running sharpish after a brisk warm-up and Serena Williams is not hanging around either.
A whistle-stop hold to 15 is followed by that strange, almost mournful, trudge around the far side of the net that she marks the end of every first game with.
Timea's turn...
Post update
Route to the semi-final
EPACopyright: EPA
First round: beat Lara Arruabarrena 6-3 6-4
Second round: beat Tereza Smitkova 6-2 6-0
Third round: beat Madison Keys (16th seed) 6-4 6-2
Fourth round: beat Petra Kvitova (4th seed) 2-6 6-0 6-3
Quarter-final: Alison Van Uytvanck 6-4 7-5
Total time on court: 6 hours 49 minutes
Average rank of opponent: 51
Post update
Route to the semi-final
EPACopyright: EPA
First round: beat Andrea Hlavackova: 6-2 6-3
Second round: beat Anna-Lena Friedsam 5-7 6-3 6-3
Third round: beat Victoria Azarenka (27th seed) 3-6 6-4 6-2
Fourth round: beat Sloane Stephens 1-6 7-5 6-3
Quarter-final: beat Sara Errani (17th seed) 6-1 6-3
Total time on court: 8 hours 5 minutes
Average rank of opponent: 76
Tale of the tape
Williams v Bacsinszky
BBCCopyright: BBC
Post update
Williams v Bacsinszky
Timea Bacsinszky told BBC Radio 5 live earlier this year how fear of her father was the driving force behind her tennis and believes "he doesn't deserve to have kids" for the way he treated her.
She calls her father a "control freak" and says of her childhood, "I was living in Switzerland and seeing all those other kids around me who had nice families, and then me on the other side."
Bacsinszky also reveals how tennis tore her family apart, ''I kind of forced my mum to divorce because I told her 'okay, it's un-livable. you cannot live that way, it's not possible."
After nearly quitting the sport two years ago, Bacsinszky says that now, "I am my own boss, I own my own life, it was quite difficult for me earlier to understand that. When you are the kid of a parent, who is that kind of pushy parent, who wants to live his dream through your life, it's difficult."
Post update
Getty ImagesCopyright: Getty Images
Schweini has a bit of previous when it comes to his and Lukas Podolski's bro-mance.
Anyway back to matters Philippe Chatrier.
If the size of the courtwalk earphones is anything to go by then this is going to be a tight match.
Both Timea Bacsinszky and Serena Williams are muffled up in giant headwear as they stride out on court...
Who will face Safarova?
Williams v Bacsinszky
So one of the question marks in the 'who will contest the French Open women's final' teaser has gone. And it has been replaced by the smiling face of 13th seed Lucie Safarova.
But there is one question mark remaining. World number one, and 19-time Slam winner, Serena Williams? Or 23rd-seed, and final rookie, Timea Bacsinszky?
Time for a fresh tactical approach from us too - here's my colleague Mike Henson to talk you through the second semi-final....
Post update
Ivanovic 5-7 5-7 Safarova
I'll tell you what Bastian Schweinsteiger is up to - he's not consoling his beloved Ana downstairs. Nope, the Germany midfielder sneaked off sharpish so he could Tweet his birthday wishes to international team-mate Lukas Podolski. This post appeared on Schweiny's official Twitter account seconds after Ivanovic's semi-final defeat was complete...
TwitterCopyright: Twitter
Post update
Ivanovic 5-7 5-7 Safarova
Piers Newbery
BBC Sport at Roland Garros
"She got there in the end, a fantastic moment for Safarova, who has had her issues with nerves in the past but overcame them at the second attempt.
"Coach Rob Steckley stands up and high-fives fellow supporters before beating his chest and pointing at Safarova. Meanwhile, Bastian Schweinsteiger troops off with the rest of the Ivanovic team. When does pre-season start at Bayern?"
Safarova reaches final
Ivanovic 5-7 5-7 Safarova
French Open finalist Lucie Safarova speaking on Court Philippe Chatrier: "It is a dream come true. I cannot believe it.
"I started slowly today but tried to keep up the level and try and play really aggressive because that was the only way to get a win.
To the Roland Garros crowd: "Thank you so much for your support. You were incredible."
APCopyright: AP
Safarova reaches final
Ivanovic 5-7 5-7 Safarova
Lucie Safarova waves and flashes a beaming smile as she takes the acclaim of the Roland Garros crowd. Then, with her back still covered in red dust, sits down on her seat, puts her head in her hands, and soaks up her moment of glory. Ana Ivanovic slopes off court out of the back door....
Former Wimbledon champion Jana Novotna: "Safarova played so well, she was not afraid and made an amazing comeback against a tough opponent in the first set and then kept cool after missing a couple of missed match points in the second."
Game, set and match - Safarova
Ivanovic 5-7 5-7 Safarova
All over! Lucie Safarova, after a few more signs of service-game nerves, finds herself with two more match points. The 13th seed puts a forehand long on the first, but her next one is hammered past Ana Ivanovic.
The Czech leftie crumbles to the clay in joy - and can now turn her attentions to a first Grand Slam final!
Getty ImagesCopyright: Getty Images
Safarova breaks
*Ivanovic 5-7 5-6 Safarova
It is like Christmas morning out on Court Philippe Chatrier. After Safarova handed over a perfectly-wrapped present to Ivanovic in the last game, the Serb returns the favour by surrendering her serve immediately. Safarova looks like a kid who has just opened a spanking new games console - and so she might. The Czech serves for the match for a second time....
Former Wimbledon champion Jana Novotna: "Ana Ivanovic showed real positivity in that game, hanging in there and waiting until she could see her shots before she went for them."
ReutersCopyright: Reuters
Ivanovic breaks back
Ivanovic 5-7 5-5 Safarova*
EPACopyright: EPA
...deuce, advantage Ivanovic, deuce, advantage Ivanovic, deuce. Even the Chatrier crowd want to see someone take this game by the scruff of the neck now, encouraging both players with a ripple of applause as they catch their breath. Then Ivanovic grabs a third break point with a sublime forehand which slides down the line to the back of the court. Back roars Safarova before the Serb forces into her into another stray backhand - that's a fourth break point. This time the seventh seed grabs her chance and Safarova must go again
Post update
Ivanovic 5-7 4-5 Safarova*
Oh Ana! Ivanovic steps forward on the attack on that break point, hammering her return too long. And she might as well have hammered a nail in her own coffin. All momentum is lost as Safarova takes us back to deuce, then claims her first match point. This will seal it....but she produces another double fault!! On we go....
Post update
Ivanovic 5-7 4-5 Safarova*
I'm never going to know what goes through your mind when you're serving for a place in a Slam final - but it must be a mix of excitement and fear. The latter comes to the fore as Safarova double faults with her first serve, then slams into the net with a forehand. She fights backs to 30-30 but then clips the tape with her second serve - break point for Ivanovic....
Post update
Ivanovic 5-7 4-5 Safarova*
Over to you, Lucie. Staring defeat square in the face, Ivanovic produces a gutsy hold to keep her flimsy dreams of a second Roland Garros final alive. Now Safarova serves for the match....
Post update
Piers Newbery
BBC Sport at Roland Garros
"Team Ana, as it's probably called, is getting very exercised in the stands as their woman struggles to get back into this match. The cheering, fist pumping, pointing and standing after winners is all very well, but it's matched by eye rolling, groaning and forehand smacking after the errors.
"Not sure Ivanovic needs to be seeing her own emotional turmoil reflected back at her every time she looks to the stands. Coach Steckley, in Safarova's corner, raises a very chilled finger after his boss smacks a forehand winner."
Post update
*Ivanovic 5-7 3-5 Safarova
ReutersCopyright: Reuters
....a looping return from Ivanovic draws Safarova into her first smash of the match - and it's a perfectly-executed winner! Advantage Safarova. A forehand winner from the Serb saves the game, but she concedes another point and this time the Czech - who is having every facet of her game tested by Ivanovic in this gruelling game - completes the job at the second attempt. Now Safarova is one break from the final....
Post update
*Ivanovic 5-7 3-4 Safarova
Safarova is two service games from the match - here's her first chance with ball in hand. The game starts well enough as a backhand volley and sloppy return from Ivanovic puts the Czech 30-0 ahead. She allows Ivanovic a point before driving a stunning, un-returnable forehand deep into the Serb's territory. That's Safarova's 15th forehand winner compared to just eight from her opponent. Hang on, back comes Ivanovic! The seventh seed targets the Safarova backhand which crumbles as Ivanovic forces deuce....
EPACopyright: EPA
Post update
Ivanovic 5-7 3-4 Safarova*
Spectators outside Philippe Chatrier are kicking back in some inflatable chairs watching this match on the big screens at Roland Garros - bet Ana Ivanovic wishes her afternoon was so easy. The Serb toils again as she clings tightly on to her serve, fending off Safarova's advances at 15-15 and 30-30 to hold.
Post update
*Ivanovic 5-7 2-4 Safarova
It appears neither woman wants to win this game - because perhaps, as our man Piers points out below, nerves are kicking in. Some wild shots from each side offer hope to the other, before Safarova takes control in deuce to move within two games of her first French Open final.
AFP/GETTYCopyright: AFP/GETTY
Post update
Ivanovic 5-7 2-3 Safarova*
Piers Newbery
BBC Sport at Roland Garros
"Ana Ivanovic dropped three points in her first three service games - she has dropped 23 in the following six. The Serb has been in a tailspin, with the tell-tale sign of her ball toss going walkabout, for the last half hour but she might just have come out of it with that service hold.
"And Safarova is three holds from her first Grand Slam final, so nerves could strike her too."
Get involved via #bbctennis or 81111 on text
Bernard Akinyamoju: "Ivanovic about to confirm the choker status again! I hope not."
Post update
Ivanovic 5-7 2-3 Safarova*
Oh dear. Court Philippe Chatrier groans, then breaks out in encouraging applause as Ana Ivanovic double faults to hand a break point to Lucie Safarova.
But that is the boost which Ivanovic needs. The Serb saves the break before a wonderful serve and volley is followed by a crunching backhand winner. Vital hold. Can that act as a catalyst for the 2008 champion?
Former Wimbledon champion Jana Novotna: "The body language from Ana Ivanovic is really slowing down. Everything that she has tried today has not been enough - Lucie Safarova is just hitting the ball too cleanly. That was a very confident game from Safarova and I think there is a little desperation creeping in for Ivanovic."
Post update
*Ivanovic 5-7 1-3 Safarova
EPACopyright: EPA
Safarova has not dropped a set so far this year at Roland Garros and it will take a remarkable effort from Ana Ivanovic to take this match into a third. The Serb is not in this contest at the moment, failing to nick even a point as Safarova holds to win her eighth game in the last nine.
Safarova breaks
Ivanovic 5-7 1-2 Safarova*
Safarova springs from defence to attack quicker than a Jose Mourinho football team - she goes a set and a break up! The Czech manoeuvres herself into a position of three break points, taking the second one to draw first blood in the second set. Ivanovic is sinking quickly....
EPACopyright: EPA
Post update
*Ivanovic 5-7 1-1 Safarova
Gutsy stuff again from Safarova. A break point for Ivanovic is wiped out by another Safarova ace, before the Serb tries to push her opponent behind the baseline and delivers another peach of a forehand to take a second break point. But more brilliant play under pressure from Safarova has Ivanovic looking to the heavens as a return ball dusts the opposite corner of the court to where she is standing. Deuce for the fourth time. Ivanovic looks annoyed as she overcooks a forehand to hand Safarova another advantage - even more so when another ace - Safarova's seventh of the match - whizzes past her eyeline. What. A. Hold.
Post update
*Ivanovic 5-7 1-0 Safarova
A tense Ivanovic spins around in disgust, slapping her thigh too, as she meekly smacks a forehand return into the net for 40-30. The 2008 French Open winner forces deuce in the next point, but sees the break-lined rug pulled from under her feet by a Safarova ace. The Czech cannot convert that advantage though, slapping into the tape from a central position. On we go....
APCopyright: AP
Post update
Ivanovic 5-7 1-0 Safarova*
Ivanovic opens the second set as she looks to hit straight back and end that miserable run of five losing games in a row. No room for the Serb to lose an early break here.
Safarova's forehand winner levels at 30-30 but a flush forehand from Ivanovic eases any lingering tension - as does a crashing ace for the hold. Phew....
Post update
Ivanovic 5-7 Safarova
Piers Newbery
BBC Sport at Roland Garros
"Safarova is on target to break the top 10 for the first time next week, and could go as high as number six if she wins the title. Canadian Rob Steckley has been a driving force behind her improvement - he's the bearded Canadian sitting in her player box and doing a good impression of a surf instructor.
"The former world number 464 is a bit of a character and has worked wonders with Safarova. They clearly get on well."
Former Wimbledon champion and two-time French Open semi-finalist Jana Novotna: "Lucie looked like she was trying too hard early on, going for too perfect a shot and since she has calmed down she has started hitting the ball more cleanly and finding the angles.
"That is why you have to focus on yourself, there will always been an opportunity to get back into a match and you have to make sure you are able to take it."
Game and first set - Safarova
Ivanovic 5-7 Safarova
Ivanovic is melting in the Parisian sun quicker than an exposed ice lolly. Safarova is not only negating Ivanovic's previously dominant forehand now, the leftie is now controlling the play with her own forehand.
Ivanovic cannot make any incisions in the Safarova serve as the Czech holds to love to take the first set. That was *cliche alert* a real set of two halves....
Safarova breaks
Ivanovic 5-6 Safarova*
APCopyright: AP
Well, well, well. Who saw this one coming? Not me. Seventh seed Ana Ivanovic was coasting towards the first set not too long ago, but in the time it took you to finish your late lunchtime sandwich she is now staring a deficit in the face. Safarova nabs two break points and takes the first one to move within a service hold of the opener.
Post update
*Ivanovic 5-5 Safarova
All square again. The Safarova serve is under the microscope again as Ivanovic, eyes fixed on the high ball, dispatches a drive volley clinically for 30-30. But, not for the first time, Safarova eases the pressure with an ace and then completes the job when Ivanovic misses the target with a forehand.
Former Wimbledon champion and two-time French Open semi-finalist Jana Novotna: "Lucie Safarova has always been a little in the shadow of Petra Kvitova back in the Czech Republic. It is really nice for Lucie to be able to come out and take centre stage. There will be lots of people glued to their televisions back home."
Safarova breaks back
Ivanovic 5-4 Safarova*
ReutersCopyright: Reuters
When the going gets tough, Safarova gets going! Some gutsy returns from the Czech forces a double break point just when she needs them. One goes begging when a heavy Safarova return flies past the baseline. But then the 13th seed - who hasn't dropped a set at Roland Garros this year - produces a worldy of a forehand return which dusts the final millimetre of the tramline.
Post update
*Ivanovic 5-3 Safarova
Safarova is serving to stay in the first set and, despite coughing up a double fault at 15-0, takes the next three points with relative ease. A forehand winner is followed by a backhand winner, before Ivanovic goes long. But the Serb knows she is now serving for the opening set....
Post update
Ivanovic 5-2 Safarova*
ReutersCopyright: Reuters
The Ivanovic serve has not really been questioned by 13th seed Safarova - but now it is. The Czech forces deuce, after being 40-15 behind, with a stunning backhand winner. But Ivanovic steps up a gear, luring Safarova into two unforced backhand errors, for the hold. "Come on!" shouts the Serb as we see the first real burst of emotion from either woman.
Former Wimbledon champion and two-time French Open semi-finalist Jana Novotna: "This is very smart play by Ana Ivanovic, putting top-spin on her forehand into Lucie Safarova's backhand. It is kicking up very fast and high and Safarova is struggling to control it off that wing.
"There have been quite a lot of unforced errors from both players so far. But both are continuing to go for their shots. There are a lot of mistakes, but also a lot of winners."
Post update
*Ivanovic 4-2 Safarova
Piers Newbery
BBC Sport at Roland Garros
APCopyright: AP
"When she emerged on the scene a decade ago, Ivanovic was noted for her heavy, flat forehand and tendency to clench her fist after every successful point. Ten years on and those trademarks are still in place, the fist-clench getting a good workout in a dreamy 10 minutes for the Serb.
"And while not wanting to divert attention to the boyfriend in the crowd, it's remarkable how Bastian Schweinsteiger is able to clap louder than anyone else in a stadium of 17,000 people."
Post update
*Ivanovic 4-2 Safarova
That second break point goes begging for Ivanovic, as the pair continue to trade blows in what could be a pivotal game in this opening set. Safarova hauls herself back from the brink, teeing up two game points of her own, but a classy backhand from the Serb takes us to a third deuce.
Both players are trying to ask questions of the other's backhand - and a long rally ends when Ivanovic's crumbles first. Then Safarova blasts down a quick first serve which is too hot for Ivanovic to handle as the Czech saves a potentially crucial hold.
Post update
*Ivanovic 4-1 Safarova
Getty ImagesCopyright: Getty Images
Safarova is under pressure on her serve again. A second double fault from Safarova contributes to another Ivanovic break point. The Serb can only slam a forehand return into the tape for deuce, but is given another chance when Safarova goes long.
The Czech has found the target with 84% of her first serves - but only 63% have been won.....
Post update
Ivanovic 4-1 Safarova*
Can Safarova build on that morale-boosting hold? In a word...no. Two thumping serves ping off the Roland Garros clay and behind Safarova as a pair of aces give Ivanovic a 40-0 lead following an opening forehand winner. The Czech nabs a point back before grimacing when a backhand return lands inside the tramlines to give Ivanovic the fifth game.
Post update
*Ivanovic 3-1 Safarova
Getty ImagesCopyright: Getty Images
Lucie Safarova needs a comfortable hold here - and that is exactly what she gets. The left-hander wraps up the game in a matter of seconds, thanks to a couple of forehand winners and sloppy Ivanovic returns. Confidence booster....
Former Wimbledon champion and two-time French Open semi-finalist Jana Novotna on BBC Radio 5 live sports extra: "Lucie Safarova has had a good first serve percentage so far through the tournament and she really has to keep that up because Ana Ivanovic will be all over the second serve.
"She does not really look into the match yet. Ivanovic is keeping her under so much pressure."
Listen live via the audio icon at the top of this page.
Post update
Ivanovic 3-0 Safarova*
Everyone in the Chartier crowd is donning a straw hat - à la the Man from Del Monte (ask your dads) - as the strong sun beats down on Roland Garros. Ivanovic maintains the strong start to her service game, winning four points on the trot after allowing Safarova the luxury of the first point. The Serb is looking composed and extremely confident....
Ivanovic breaks
*Ivanovic 2-0 Safarova
APCopyright: AP
Safarova builds up a 30-0 lead, only to throw that away with an unforced backhand error and a double fault.
That gives Ivanovic hope of an early break and, although Safarova saves with a 171 km/hr ace, a great forehand winner from the Serb sticks her within another point of a 2-0 lead.
This time, she snaffles that chance as Safarova finds the net with a loose backhand. First blood to Ivanovic....
Get involved on #bbctennis and 81111 on text
Who will make Saturday's final?
Freddie Higgs: "So happy for Ana Ivanovic she has played brilliantly and it's time for her to recreate '08"
Kayley Jay: "OK, I've shaken up my magic 8 ball, it says Safarova v Bacsinszky. Asked if it was kidding; reply 'Don't bet on it'."
Post update
Ivanovic 1-0 Safarova*
Ana Ivanovic has the honour of serving first, her first effort lightly dusting the net, before the second is smacked long by the Czech. Ivanovic, decked out in a black dress, confidently sweeps a forehand winner past her opponent before teeing up three game points with a blistering ace.
A brief glimmer of hope for Safarova, who then palms a backhand return into the net. Solid opening hold by Ivanovic.
Post update
Ivanovic v Safarova
Getty ImagesCopyright: Getty Images
Ready? As Jim Carrey would say in The Mask - it's show-tiiiiiime! One last swig of French-branded water for each of these potential finalists before they step up to the clay to a generous round of applause....
Post update
Ivanovic v Safarova
Piers Newbery
BBC Sport at Roland Garros
Getty ImagesCopyright: Getty Images
"Ana Ivanovic has been one of the stories of this French Open, finally breaking back into the final four at a Grand Slam for the first time since she won the title here in 2008. The Serb became world number one that day, staying at top spot for 12 weeks, and it seemed likely she would be battling for the major prizes for years to come.
"However, she had slipped back into the pack of second-week contenders until this week. Roared on by boyfriend Bastian Schweinsteiger, the German World Cup winner, and a team of large and heavily branded men in her support team, the Serb has become a force once again."
Post update
Ivanovic v Safarova
Safarova is the first to emerge into the Paris sun, waving almost shyly to the crowd building up inside Court Philippe Chatrier, before she is quickly followed by Ivanovic. The pair stare across the net at each other for the first time, knocking up before they get down to the serious business of a French Open semi-final.
"Trois minute" says the umpire. That's three minutes until we begin to me and you....
Post update
Ivanovic v Safarova
We catch a quick glimpse of Ana Ivanovic as she prepares to walk out on to a sunny Philippe Chatrier. The Serb, with imaginary racquet in hand, slashes a forehand and then a backhand as she limbers up in the locker room. Then the Serb does some quick on-the-spot sprinting - it is all about the footwork you see. The players are almost ready....
Get involved on #bbctennis or 81111
Who will make Saturday's final?
Adam Nicholls: Serena in straight sets. Ana is 3-5 against Safarova so it will be tough for her to do it. But I am in #TeamAna all the way!
Route to the semi-final
Lucie Safarova
Getty ImagesCopyright: Getty Images
First round: beat Anastasia Pavlyuchenkova 7-6 (8-6) 7-6 (11-9)
Second round: beat Kurumi Nara 6-2 6-0
Third round: beat Sabine Lisicki (20th seed) 6-3 7-6 (7-2)
Fourth round: beat Maria Sharapova (second seed) 7-6 (7-3) 6-4
"The temperature has leapt significantly to the mid-20s today and Roland Garros is bathed in sunshine, apparently for the foreseeable. You know the weather is good here when there are spectators on court before the match actually starts.
"While Goran Ivanisevic and Carlos Moya take on a couple of ball kids in legends' hi-jinx on Court Suzanne Lenglen, the serious business is about to get under way on Chatrier. There are even people in the VIP box already. And not just staff."
Get involved on #bbctennis and 81111
Who will make Saturday's final?
A Scott on text: You're way off with your Ana Ivanovic tip, reckon she will lose worse than Bacinsinszky. A Safarova/Williams final.
Post update
Ivanovic v Safarova
APCopyright: AP
What do you mean you don't know much about Lucie Safarova? Luckily we are here to help.
The Czech leftie is contesting her second Slam semi-final, having lost in the last four to eventual champion Petra Kvitova at Wimbledon last year.
The 28-year-old 13th seed has not yet dropped a set at Roland Garros last year and, of course, beat reigning champion Maria Sharapova in the fourth round.
"She's a great player. She showed that many times. She had a great match against Maria," says Ivanovic.
"It's going to be tough match-up for me. She's obviously lefty, gets really lots of balls back very heavy, very aggressive."
Back in familiar territory
Ivanovic v Safarova
BBCCopyright: BBC
Ivanovic eyes another final
Ivanovic v Safarova
EPACopyright: EPA
Ana Ivanovic won her first Slam as a 20-year-old at Roland Garros in 2008 - but hasn't really fulfilled her potential since. So understandably she is "very, very thrilled" to reach her first French Open semi-final since 2008.
"It's been a long road and hard work," says the 27-year-old, who was also a Australian Open finalist in 2008.
"Obviously you know seven years ago it was completely different experience. I was a lot younger and I sort of didn't have the experience. I just was so excited and I felt like, you know, I can achieve anything.
"At that point I had so many victories and so many good results. Maybe I didn't appreciate it as much as I do now."
Post update
A gentle hum of excitement can be heard across Roland Garros as the French tennis fans head towards the Philippe Chatrier turnstiles. Hope they have plenty of suncream and protective hats in their bags, the sun is shining and the weather is sweet as Bob Marley would say. About 15 minutes until Ivanovic and Safarova are kicked out of the locker room....
Tale of the tape
Ivanovic v Safarova
BBCCopyright: BBC
Get involved
#bbctennis or 81111 on text
Shake up your magic eight ball. Flip your lucky coin. Give you tea bag a predictive poke.
We are after your predictions today.
Come Saturday afternoon, which two of these four players are going to be dirt-wrestling on the terre battue for the title?
Williams v Ivanovic is your banker I guess, but are there any takers for a Safarova v Bacsinszky showpiece?
Hit us on #bbctennis on Twitter and 81111 on text with your best guesses and reasons why.
Bonjour mes amis! And welcome to the business end of the French Open - today we are entering semi-final territory.
Four women must squeeze into two final spots.
Either seventh seed Ivanovic or Safarova - the woman who sent reigning champion Maria Sharapova packing - will nab the first one when they meet on Court Philippe Chatrier about 14:00 BST.
And once that match is decided, we will find out if Timea Bacsinszky can cause a shock on the scale of Robin Soderling by beating Serena Williams.
Post update
Getty ImagesCopyright: Getty Images
Honk, honk! Move out of the way ladies - the Serena juggernaut is powering through Paris.
Williams might not be cruising along in fifth gear at Roland Garros, but the road ahead is wide open and heading straight towards a 20th Grand Slam singles' title.
Can anyone derail the American? Swiss 23rd seed Timea Bacsinszky will be the latest to have a go later today. And if she can't stop Serena then only former French Open champion Ana Ivanovic or Lucie Safarova - who has not beaten the world number one in eight attempts - are the final roadblock.
Post update
Getty ImagesCopyright: Getty Images
Close your eyes, relax and let your mind wander forward to this Saturday.
You may picture Lionel Messi scoring as Barcelona ease past Juventus to win the Champions League final.
You may also visualise Serena Williams collapsing to the Roland Garros clay in celebration. And then being presented with the Coupe Suzanne Lenglen after winning the French Open women's singles title.
Williams, like Barcelona, is the overwhelming favourite to stick her mitts on more silverware this weekend. But, as we know, sport has a habit of throwing up the unexpected....
Live Reporting
Jonathan Jurejko and Mike Henson
All times stated are UK
Get involved
Getty ImagesCopyright: Getty Images EPACopyright: EPA EPACopyright: EPA EPACopyright: EPA APCopyright: AP Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images EPACopyright: EPA Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images APCopyright: AP Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Roland Garros/TwitterCopyright: Roland Garros/Twitter ReutersCopyright: Reuters Getty ImagesCopyright: Getty Images BBCCopyright: BBC Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images TwitterCopyright: Twitter APCopyright: AP EPACopyright: EPA EPACopyright: EPA BBCCopyright: BBC Getty ImagesCopyright: Getty Images TwitterCopyright: Twitter APCopyright: AP Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images ReutersCopyright: Reuters EPACopyright: EPA ReutersCopyright: Reuters EPACopyright: EPA AFP/GETTYCopyright: AFP/GETTY EPACopyright: EPA EPACopyright: EPA APCopyright: AP APCopyright: AP ReutersCopyright: Reuters ReutersCopyright: Reuters APCopyright: AP Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images APCopyright: AP Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images APCopyright: AP BBCCopyright: BBC EPACopyright: EPA BBCCopyright: BBC @RolandGarros/TwitterCopyright: @RolandGarros/Twitter Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images
Latest PostPost update
So Saturday's final will be Serena Williams v Lucie Safarova.
Safarova will have to overturn a 8-0 losing record against Williams if she is to lay her mitts on her first Grand Slam title. But with Williams in such unpredictably out of sorts form you never know.
See you here for that and possibly the small matter of the men's semi-finals tomorrow. Ciao for now.
Post update
The drama was in the detail, but let's have a look at the stats behind that see-sawing merry-go-round of a match.
Williams-Bacsinszky
Aces: 8-4
First serve %: 57-70
Double faults: 0-3
% pts won on first serve: 78-60
% pts won on second serve: 47-30
Winners: 37-26
Unforced errors: 30-24
Post update
The television cameras follows Serena Wiliams back into the bowels of Philippe Chatrier, capturing her reunion with coach and partner Patrick Mouratoglou.
Williams is too shattered to lift her arms to hug the Frenchman. She looks out on her feet. As she has for the whole of the match.
Mouratoglou points the way to somewhere out of shot - possibly the medicine cabinet.
Williams through to final
Williams 4-6 6-3 6-0 Bacsinszky
Piers Newbery
BBC Sport at Roland Garros
"It was Williams who began the match close to tears, it's Bacsinszky who leaves the court in floods. She had looked on course for a first major final but Williams somehow managed to hit back from a set down for the fourth time this tournament - the first time she has done that at a Grand Slam. Coach Patrick Mouratoglou gives her a hug backstage and then guides her gingerly down the stairs away from the cameras."
Get involved
via text on 81111
Rebecca: Serena is a genius. Her antics have kept the crowd sympathetic to her. Otherwise they would have been cheering for the Swiss player.
Anuj, Harrow: All the Serena critics should show some more respect. This is the greatest female player of all time! Why would she need to fake an illness to gain an advantage?
Martin H, Coventry: Suspect that Serena will be picking up the trophy on Saturday in Paris and an Oscar in Hollywood later in the year.
Post update
Serena Williams: "I don't know how I did it. If I was going to lose, I didn't want to lose without a fight. I just tried to find some energy form somewhere. I hope I will get better before Saturday. I am ill."
Williams through to final
Williams 4-6 6-3 6-0 Bacsinszky
Well, that was a hard day at the office.
One extraordinary cross-court pass, from well out wide and a split legged sliding stance, was the sort of thing that Williams would be proud of at full fitness.
She sways and staggers to her chair after getting some sincere and sporting congratulations from Timea Bacsinszky.
Bacsinszky is strugging to hold back tears. So is Williams. Not a dry eye on the court.
Williams breaks
*Williams 4-6 6-3 5-0 Bacsinszky
Timea Bacsinszky has come off the boil certainly, but Serena Williams is just slinging pure power off either wing.
She crashes away a forehand on the first of two break points at 15-40.
Off she slopes towards the changeover chair. Twenty-seven minutes on the clock for this set and a lot of that has been taken up by Williams's go-slow between points.
Post update
Williams 4-6 6-3 4-0 Bacsinszky*
Heaving shoulders, hacking cough and Serena Williams is still ill.
Simon Briggs diagnoses bronchitis from the BBC Radio 5 live sports extra commentary box. But the form and prospects are looking increasing perky.
The American holds to 15 and a hotel room bed and honey and lemon drink might not be far off.
Post update
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
"Lucie Safarova will be happy with what she's seeing at the moment. She's got a wounded animal on one side of the net and a psychologically-damaged player on the other."
Post update
Piers Newbery
BBC Sport at Roland Garros
"The momentum might have shifted dramatically on court but there's not much change off it, with Williams taking on the biggest ice towel of the day and leaning her head in her hand during the two-minute break. Bacsinszky looks unperturbed as she takes on water, perhaps resigned to the inevitable?"
Get involved
via text on 81111
Rose, Oxford: What a surprise. Back she comes. I feel sorry for who ever she plays. Not very sportsmenlike.
Get involved
#bbctennis
Curtis: Bacsinszky's forehand is pretty much non-existent, no wonder Serena is peppering it now, easy third set for Serena.
Ayo Obit: Problem is Timea is primarily a counter-puncher and Serena, even a half-fit Serena, does NOT lose to counter-punchers!
Williams breaks
*Williams 4-6 6-3 3-0 Bacsinszky
Curtains? I fear it might be.
Timea Bacsinszky skirts around a couple of break points as Serena Williams plops long on the backhand.
But she plummets a double-break behind on a third as he strays beyond the baseline.
Post update
Williams 4-6 6-3 2-0 Bacsinszky*
Serena Williams hammers away a backhand punch and hollers to the skies as she backs up the break.
You could say that Timea Bacsinszky had her chances at 15-40. But are they really chances when you get two serves fizzed around your lugholes on both break points?
Williams's coach Patrick Mouratoglou is earning his corn today. He is out of his seat, clenching teeth, fist and anything else he has got in celebration. He'll give himself a hernia doing that.
Get involved
via text on 81111
Jaime, Huntingdon: Personally I suspect Serena enjoys the added attention she gets when she wins while being "unwell". All too common I'm afraid. Perhaps being so dominant makes such self-indulgence possible.
Williams breaks
*Williams 4-6 6-3 1-0 Bacsinszky
That is kamikaze tennis from Timea Bacsinszky.
From 30-0 down, Serena Williams lands a whopping roundhouse inside-out forehand on return to move to 30-30.
No need for panic. Plenty of margin for error.
But Bacsinszky loses her composure quite dramatically, cracking two inviting mid-court dollies, bouncing high and gentle for her to put away, outside the lines.
Williams with a freebie of a break.
Get involved
via text on 81111
John Head, London: Serena is always most vicious when up against it. Memories of Australian Open quarter-final (2010) with Azarenka coming to the fore. She was 6-4 4-0 down in that one, I'd imagine this is not cause for concern to her.
Post update
Williams 4-6 6-3 Bacsinszky*
Out they come for the third...
Serena Williams is still not raising her pace above octogenarian levels if there is not a live tennis ball to chase.
Get involved
#bbctennis
RieruM: If there's one thing I've learned from Roland Garros 2015, is that if Serena loses the first set it doesn't mean much!
Michael S: Serena to make a miraculous recovery and win the third set 6-0?
Post update
Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra
"Sheer bloody-mindedness, sheer brilliance, from Serena Williams when she is clearly not 100%. We are going the distance."
Williams wins the second set
Williams 4-6 6-3 Bacsinszky*
Serena Williams racks up two set points at 40-15.
Timea Bacsinszky shoots them down.
But Williams rolls out the heavy artillery, booming down a bazooka ace to set up a third that proves the charm. Into a decider.
Serena with the momentum or Timea without the illness? Let's find out.
Williams breaks
*Williams 4-6 5-3 Bacsinszky
Coach Patrick Mouratoglou leads the cheer squad as Serena Williams sniffs blood, advances and slaps away the forehand drive volley at break point and 30-40.
Timea Bacsinszky is being pulled out of shape by the top seed's power when the rallies are allowed to develop.
She doesn't seem able to destabilise Williams, or force her into lateral movement, as she did in the first set.
Get involved
#bbctennis
David Jack: People making ludicrous claims that Williams is faking her illness. Yeah, cos that's a brilliant tactic isn't it.
PS: Sick of Williams' antics which have been fairly consistent last few years.
Post update
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
"Tactically it is quite a dilemma for Bacsinszky. It is always an awkward scenario when your opponent is struggling. The dilemma is that you try to work them around the court, get them running and losing more energy, but then you can lose your own game."
Post update
Williams 4-6 4-3 Bacsinszky*
Serena Williams may only be operating in second gear, but she is red-lining it all the way in the shots that he does hit.
Successive crackerjack aces down the middle seal the game and save the American from having to expend any more energy then she has to.
She is ahead on the scoreboard again. A crucial time in the match now. The last thing that Bacsinszky should do is give her opponent the tonic of a break.
Get involved
#bbctennis
Nick Powell: Can't tell if Serena is faking or not, I suspect not, but how many times have we seen her in this state before dominating.
Williams breaks
*Williams 4-6 3-3 Bacsinszky
Deary me.
Timea Bacsinszky has been all-out attack so far in the match and it has served her well.
But the purple patch fades slightly as the Swiss boshes down the line and out to allow Serena Williams to 15-40 and two break points.
She converts the first as Bacsinszky fails to crowbar a backhand off the dust.
Post update
Piers Newbery
BBC Sport at Roland Garros
"While Bacsinszky holds up a deflated ball to the umpire at the changeover, her opponent is looking similarly beaten on the opposite chair. Williams cannot sit up straight and is coughing and spluttering, looking tearful once again."
Post update
Just in reply to Philip in the tweet below, I don't think that anyone thinks that Serena Williams is faking an illness.
It is just the way she seems to be coping with it is to act out every cough, splutter and ache in triplicate.
There is more swooning and swaying at the changeover.
Post update
Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra
"I still think there's plenty of mileage left in this match - but it is getting very, very tight for Williams."
Bacsinszky breaks
Williams 4-6 2-3 Bacsinszky*
Timea Bacsinszky is all over the Serena Williams serve like a an angry rash.
Two break points have already disappeared down the swanny, when the Swiss breaks out a drop-shot return winner to Serena Williams' rocket. Extraordinary.
Williams sees off another two break points but finally at the sixth time of asking, Bacsinszky has the break as Williams cuffs a backhand wide.
Get involved
#bbctennis
Philip Farrell: Come on guys, two text messages implying Serena is faking it seems a bit harsh. She doesn't look well.
Post update
*Williams 4-6 2-2 Bacsinszky
One forehand error and three off the backhand seal Serena Williams's demise to love.
Plenty of pop in Timea Bacsinszky's groundstrokes to force those mistakes, but it looks like Williams has suffered a set-back.
There has been more twists and turns in her performance - and dare I say it hammy acting - than a Brazilian telenovela.
Post update
Williams 4-6 2-1 Bacsinszky*
Maybe there was a swig of WD40 amid all the isotonic.
Serena Williams looks like she is moving a little more freely suddenly, Her foot movement is busier, her forehand arm is swinging easier and she holds her serve with relative ease.
Have we started the upturn of the Williams U-turn in this match?
Get involved
via text on 81111
Chris, London: Amazing how Serena can look like she will collapse in between points and yet still the ball as hard as always during the point.
Post update
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
"Serena is making a lot of hand gestures - 'all is against me,' she says. 'Even the gods are smiling on my opponent.' It would be an amazing comeback from Serena considering all the spluttering and almost fainting she is doing. Assuming she is not exaggerating her illness, it would be remarkable to get out of this position."
Post update
*Williams 4-6 1-1 Bacsinszky
Serena Williams looks exasperated as a Timea Bacsinszky forehand snags the wire looping up, over her shoulder and in to seal the game for the Swiss.
I think that Williams is playing this match to an internal soundtrack of sobbing violins. Everything is against her.
If and when she stops feeling sorry for herself and starts to fight back against whatever is afflicting her, she has a chance.
Get involved
via text on 81111
John, London: Granted, Serena Williams doesn't look well - but seems like she's employing the old tactic of 'Laying it on thick' - cue miraculous recovery.
Get involved
#bbctennis
Mark Johncock: I may be cynical but what are the odds of Serena suddenly feeling better if she manages to get ahead in second set?
Safarova reaches final
Ivanovic 5-7 5-7 Safarova
French Open finalist Lucie Safarova in her post-match news conference: "It's slowly sinking in that I've reached the final...the happiness is unreal!
On closing out the semi-final win: "I think when I finally realised I could be in the final I was overthinking."
Post update
Williams 4-6 1-0 Bacsinszky*
Do you remember Serena Williams having to withdraw from the doubles event at Wimbledon last year because of a virus?
If not you can check the video here.
She was a compete shambles that day. Unable to throw the ball up straight, serves hopping tamely into the net on the bounce.
Williams is not that bad today, but she is not much better.
She scrapes through a service hold, but her body language screams that she wants off court and out of there.
Post update
Kheredine Idessane
BBC Scotland at Roland Garros
"How on Earth did Bacsinskzy stay in that point? Wonderful defending, almost Andy Murrayesque, making her opponent make one more shot when Serena looked like she had the point won two or three times. Then she was made to play the extra shot and missed. Incredible."
Bacsinsky wins first set
*Williams 4-6 Bacsinszky
Lukas Rosol, Steve Darcis, Sergiy Stakhovsky.
I reckon that Timea Bacsinszky could be about to join an elite band of giant-killers.
The Swiss shows no mercy, forcing an apparently suffering Serena Williams into shuttle runs at the back of the court to defend set point at 40-15.
Williams takes on the role of line judge, calling a Bacsinszky groundstroke long and convincing the umpire of her case as she clambers out of her high chair for a better look.
A rolling forehand across court saves the second set point for Williams, but Bacsinszky shows that she has stomach for the fight, blasting away a corking forehand to set up a third from deuce.
Post update
Piers Newbery
BBC Sport at Roland Garros
"Williams wraps herself in towels at the changeover and asks the umpire, 'That's not the set is it? Because they're sweeping the lines.' She then buries her head in an ice towel, and takes a glug of water.
"The world number one is in real trouble; hard to see how she finishes this match, let alone as the winner."
Post update
Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra
"Serena often walks slowly around the court in the early stages of matches, but she is clearly struggling - no doubt about it. Now she is wrapping an ice towel around her forehead. If you've got a headache and then are playing sport in 28C heat, it is not a pleasant place to be."
Post update
Williams 4-5 Bacsinszky*
Serena Williams is struggling here.
She has held to 30, but the story is not the scoreboard.
The American looks to be on the point of tears, mopping her brow between points, blinking as she stares downcourt, and hobbling to her seat at the changeover.
If she is playing possum to try and lure Bacsinszky into a false sense of security, it is an Oscar winning performance.
Bacsinszky to serve for the opening set.
Safarova reaches final
Ivanovic 5-7 5-7 Safarova
Beaten semi-finalist Ana Ivanovic in her post-match news conference: "I'm really proud of what I achieved in these two weeks. I'm aware that there's still room for improvement and that is the exciting part."
Post update
Post update
*Williams 3-5 Bacsinszky
Timea Bacsinszky is showing no signs of stuttering or faltering.
The Swiss gets a chunky slice of luck with a thick netcord that bounces her way, but there was nothing streaky about the rest of the game.
Get involved
#bbctennis
Bernie Austin: I like what Bacsinszky is doing so far Serena needs her A game quickly! Can she maintain this level?
Post update
Williams 3-4 Bacsinszky*
Serena Williams bellows a "C'mon" down court after bashing away a backhand. That was directed at herself as much as Timea Bacsinszky or her camp.
She is trying to rev herself up. Will it take the loss of the first set to jump-start her game? Or is not going to be able to fight off whatever is ailing her as well as Bacsinszky?
Serena is coughing heartily at the changeover...
Bacsinszky is two holds away...
Post update
BBC Radio 5 live sports extra
American journalist, and 5 live sports extra co-commentator, Courtney Nguyen: "Bacsinszky is completely outplaying Serena so far. We know Serena's quality but Bacsinszky is doing what so many fail to do when under pressure against the American - that is getting on top of the things given by Serena. She is keeping Serena running and on the defensive."
Post update
*Williams 2-4 Bacsinszky
That won't make Serena feel any better.
Timea Bacsinszky is showing some very unSwiss aggression, snarling at anything short and walloping winners.
A hold to consolidate the break and clear blue water between her and the world number one.
Post update
Good call Ali.
Williams was clutching a towel to her forehead and had ice packs round her neck during the changeover, doing her best impression of an Austin-era debutante with a fit of the vapours.
Intriguing.
Get involved
#bbctennis
Ali: Can't get used to Serena's body language between points. She looks uninterested! Injured? Unwell? Poker face?
Post update
*Williams 2-3 Bacsinszky
BBC Radio 5 live sports extra
American journalist, and 5 live sports extra co-commentator, Courtney Nguyen: "Serena Williams doesn't give you much but whatever she has given Bacsinszky has taken. It has been a perfect start for Bacsinszky, she has managed to shrink the court a little bit and show Serena that she has to deliver that little bit more to get past her.
"Bacsinszky is clear in her mind and is clear in her game plan. What a return to gain that break!"
Bacsinszky breaks
*Williams 2-3 Bacsinszky
Timea Bacsinszky works up a break point at 30-40, but, even under the weather, Serena Williams has that serve to cling to.
One right up on the apex of the service box knocks Bacsinszky back a step. But the Swiss is not to be denied.
A rasping return winner from the underdog earns a pat of applause from Wiliams, a glorious backhand lob earns another bite at the break cherry and a crunching return sends her back to her stool ahead on the scoreboard for the first time.
Post update
Williams 2-2 Bacsinszky*
Nice!
Timea Bacsinszky bops a forehand down the line, before closing out the game with a spicy ace.
Serena Williams has been a slow starter in previous rounds this fortnight and she is not chasing too hard.
"Get on the balls of your feet." Is probably what coach Patrick Mouratoglou is shouting from the players box.
The heat is on
Williams 2-1 Bacsinszky*
Piers Newbery
BBC Sport at Roland Garros
"Bacsinszky might hail from Lausanne but she could relish the toasty conditions on Chatrier today after enjoying the best run of her career in Mexico earlier this year. The Swiss won 10 matches in a row as she took the titles in Acapulco and Monterrey. The unofficial (my phone) temperature of 26C would not normally trouble Florida-resident Serena, but she has felt unwell throughout the tournament."
Murray watch
News from Roland Garros ground control...
Andy Murray has been assigned second use of Court Philippe Chatrier tomorrow for his semi-final against Novak Djokovic.
Fair enough. It is a match that demands headline billing.
However it means that we have no definite start time.
Murray will be on court once Jo Wilfried Tsonga and Stan Wawrinka - who start at 12:00 BST - are finished in the other last-four match.
Tsonga and Wawrinka have broken through the four-and-half-hour barrier in their previous two meetings at Roland Garros.
A traditional Friday early knock-off and you might be back from work in time for the meat of the match.
Sarafova reaches final
Ivanovic 5-7 5-7 Safarova
Post update
Williams 2-1 Bacsinszky*
Ominous.
Serena Williams bruises down four beefy serves as Timea Bacsinszky feels the top seed's full force.
It is like sticking your head out of the window of the Tokyo-Kyoto express train facing the Williams' serve.
Post update
*Williams 1-1 Bacsinszky
Ooh la la.
Timea Bacsinszky produces a beautifully controlled drop volley that is far out of the reach of the onrushing Serena Williams. That stops the rot at 0-30. It was so good that Marion Bartoli - on commentary for British television - couldn't help herself from reverting back to her mother tongue in her delight.
Bien joué indeed.
Bacsinszky does decently from deuce as well, stuffing away a second serve down the middle when Williams was sniffing around like a bloodhound.
A good hold. But how much variation can the Swiss bring to her serve to keep it out of reach?
Post update
Williams 1-0 Bacsinszky*
Take those lazy stereotypes about French time-keeping and efficiency and shove them in the shredder.
We are out and running sharpish after a brisk warm-up and Serena Williams is not hanging around either.
A whistle-stop hold to 15 is followed by that strange, almost mournful, trudge around the far side of the net that she marks the end of every first game with.
Timea's turn...
Post update
Route to the semi-final
First round: beat Lara Arruabarrena 6-3 6-4
Second round: beat Tereza Smitkova 6-2 6-0
Third round: beat Madison Keys (16th seed) 6-4 6-2
Fourth round: beat Petra Kvitova (4th seed) 2-6 6-0 6-3
Quarter-final: Alison Van Uytvanck 6-4 7-5
Total time on court: 6 hours 49 minutes
Average rank of opponent: 51
Post update
Route to the semi-final
First round: beat Andrea Hlavackova: 6-2 6-3
Second round: beat Anna-Lena Friedsam 5-7 6-3 6-3
Third round: beat Victoria Azarenka (27th seed) 3-6 6-4 6-2
Fourth round: beat Sloane Stephens 1-6 7-5 6-3
Quarter-final: beat Sara Errani (17th seed) 6-1 6-3
Total time on court: 8 hours 5 minutes
Average rank of opponent: 76
Tale of the tape
Williams v Bacsinszky
Post update
Williams v Bacsinszky
Timea Bacsinszky told BBC Radio 5 live earlier this year how fear of her father was the driving force behind her tennis and believes "he doesn't deserve to have kids" for the way he treated her.
She calls her father a "control freak" and says of her childhood, "I was living in Switzerland and seeing all those other kids around me who had nice families, and then me on the other side."
Bacsinszky also reveals how tennis tore her family apart, ''I kind of forced my mum to divorce because I told her 'okay, it's un-livable. you cannot live that way, it's not possible."
After nearly quitting the sport two years ago, Bacsinszky says that now, "I am my own boss, I own my own life, it was quite difficult for me earlier to understand that. When you are the kid of a parent, who is that kind of pushy parent, who wants to live his dream through your life, it's difficult."
Post update
Schweini has a bit of previous when it comes to his and Lukas Podolski's bro-mance.
Anyway back to matters Philippe Chatrier.
If the size of the courtwalk earphones is anything to go by then this is going to be a tight match.
Both Timea Bacsinszky and Serena Williams are muffled up in giant headwear as they stride out on court...
Who will face Safarova?
Williams v Bacsinszky
So one of the question marks in the 'who will contest the French Open women's final' teaser has gone. And it has been replaced by the smiling face of 13th seed Lucie Safarova.
But there is one question mark remaining. World number one, and 19-time Slam winner, Serena Williams? Or 23rd-seed, and final rookie, Timea Bacsinszky?
Time for a fresh tactical approach from us too - here's my colleague Mike Henson to talk you through the second semi-final....
Post update
Ivanovic 5-7 5-7 Safarova
I'll tell you what Bastian Schweinsteiger is up to - he's not consoling his beloved Ana downstairs. Nope, the Germany midfielder sneaked off sharpish so he could Tweet his birthday wishes to international team-mate Lukas Podolski. This post appeared on Schweiny's official Twitter account seconds after Ivanovic's semi-final defeat was complete...
Post update
Ivanovic 5-7 5-7 Safarova
Piers Newbery
BBC Sport at Roland Garros
"She got there in the end, a fantastic moment for Safarova, who has had her issues with nerves in the past but overcame them at the second attempt.
"Coach Rob Steckley stands up and high-fives fellow supporters before beating his chest and pointing at Safarova. Meanwhile, Bastian Schweinsteiger troops off with the rest of the Ivanovic team. When does pre-season start at Bayern?"
Safarova reaches final
Ivanovic 5-7 5-7 Safarova
French Open finalist Lucie Safarova speaking on Court Philippe Chatrier: "It is a dream come true. I cannot believe it.
"I started slowly today but tried to keep up the level and try and play really aggressive because that was the only way to get a win.
To the Roland Garros crowd: "Thank you so much for your support. You were incredible."
Safarova reaches final
Ivanovic 5-7 5-7 Safarova
Lucie Safarova waves and flashes a beaming smile as she takes the acclaim of the Roland Garros crowd. Then, with her back still covered in red dust, sits down on her seat, puts her head in her hands, and soaks up her moment of glory. Ana Ivanovic slopes off court out of the back door....
Post update
BBC Radio 5 live sports extra
Former Wimbledon champion Jana Novotna: "Safarova played so well, she was not afraid and made an amazing comeback against a tough opponent in the first set and then kept cool after missing a couple of missed match points in the second."
Game, set and match - Safarova
Ivanovic 5-7 5-7 Safarova
All over! Lucie Safarova, after a few more signs of service-game nerves, finds herself with two more match points. The 13th seed puts a forehand long on the first, but her next one is hammered past Ana Ivanovic.
The Czech leftie crumbles to the clay in joy - and can now turn her attentions to a first Grand Slam final!
Safarova breaks
*Ivanovic 5-7 5-6 Safarova
It is like Christmas morning out on Court Philippe Chatrier. After Safarova handed over a perfectly-wrapped present to Ivanovic in the last game, the Serb returns the favour by surrendering her serve immediately. Safarova looks like a kid who has just opened a spanking new games console - and so she might. The Czech serves for the match for a second time....
Post update
BBC Radio 5 live sports extra
Former Wimbledon champion Jana Novotna: "Ana Ivanovic showed real positivity in that game, hanging in there and waiting until she could see her shots before she went for them."
Ivanovic breaks back
Ivanovic 5-7 5-5 Safarova*
...deuce, advantage Ivanovic, deuce, advantage Ivanovic, deuce. Even the Chatrier crowd want to see someone take this game by the scruff of the neck now, encouraging both players with a ripple of applause as they catch their breath. Then Ivanovic grabs a third break point with a sublime forehand which slides down the line to the back of the court. Back roars Safarova before the Serb forces into her into another stray backhand - that's a fourth break point. This time the seventh seed grabs her chance and Safarova must go again
Post update
Ivanovic 5-7 4-5 Safarova*
Oh Ana! Ivanovic steps forward on the attack on that break point, hammering her return too long. And she might as well have hammered a nail in her own coffin. All momentum is lost as Safarova takes us back to deuce, then claims her first match point. This will seal it....but she produces another double fault!! On we go....
Post update
Ivanovic 5-7 4-5 Safarova*
I'm never going to know what goes through your mind when you're serving for a place in a Slam final - but it must be a mix of excitement and fear. The latter comes to the fore as Safarova double faults with her first serve, then slams into the net with a forehand. She fights backs to 30-30 but then clips the tape with her second serve - break point for Ivanovic....
Post update
Ivanovic 5-7 4-5 Safarova*
Over to you, Lucie. Staring defeat square in the face, Ivanovic produces a gutsy hold to keep her flimsy dreams of a second Roland Garros final alive. Now Safarova serves for the match....
Post update
Piers Newbery
BBC Sport at Roland Garros
"Team Ana, as it's probably called, is getting very exercised in the stands as their woman struggles to get back into this match. The cheering, fist pumping, pointing and standing after winners is all very well, but it's matched by eye rolling, groaning and forehand smacking after the errors.
"Not sure Ivanovic needs to be seeing her own emotional turmoil reflected back at her every time she looks to the stands. Coach Steckley, in Safarova's corner, raises a very chilled finger after his boss smacks a forehand winner."
Post update
*Ivanovic 5-7 3-5 Safarova
....a looping return from Ivanovic draws Safarova into her first smash of the match - and it's a perfectly-executed winner! Advantage Safarova. A forehand winner from the Serb saves the game, but she concedes another point and this time the Czech - who is having every facet of her game tested by Ivanovic in this gruelling game - completes the job at the second attempt. Now Safarova is one break from the final....
Post update
*Ivanovic 5-7 3-4 Safarova
Safarova is two service games from the match - here's her first chance with ball in hand. The game starts well enough as a backhand volley and sloppy return from Ivanovic puts the Czech 30-0 ahead. She allows Ivanovic a point before driving a stunning, un-returnable forehand deep into the Serb's territory. That's Safarova's 15th forehand winner compared to just eight from her opponent. Hang on, back comes Ivanovic! The seventh seed targets the Safarova backhand which crumbles as Ivanovic forces deuce....
Post update
Ivanovic 5-7 3-4 Safarova*
Spectators outside Philippe Chatrier are kicking back in some inflatable chairs watching this match on the big screens at Roland Garros - bet Ana Ivanovic wishes her afternoon was so easy. The Serb toils again as she clings tightly on to her serve, fending off Safarova's advances at 15-15 and 30-30 to hold.
Post update
*Ivanovic 5-7 2-4 Safarova
It appears neither woman wants to win this game - because perhaps, as our man Piers points out below, nerves are kicking in. Some wild shots from each side offer hope to the other, before Safarova takes control in deuce to move within two games of her first French Open final.
Post update
Ivanovic 5-7 2-3 Safarova*
Piers Newbery
BBC Sport at Roland Garros
"Ana Ivanovic dropped three points in her first three service games - she has dropped 23 in the following six. The Serb has been in a tailspin, with the tell-tale sign of her ball toss going walkabout, for the last half hour but she might just have come out of it with that service hold.
"And Safarova is three holds from her first Grand Slam final, so nerves could strike her too."
Get involved via #bbctennis or 81111 on text
Bernard Akinyamoju: "Ivanovic about to confirm the choker status again! I hope not."
Post update
Ivanovic 5-7 2-3 Safarova*
Oh dear. Court Philippe Chatrier groans, then breaks out in encouraging applause as Ana Ivanovic double faults to hand a break point to Lucie Safarova.
But that is the boost which Ivanovic needs. The Serb saves the break before a wonderful serve and volley is followed by a crunching backhand winner. Vital hold. Can that act as a catalyst for the 2008 champion?
Post update
BBC Radio 5 live sports extra
Former Wimbledon champion Jana Novotna: "The body language from Ana Ivanovic is really slowing down. Everything that she has tried today has not been enough - Lucie Safarova is just hitting the ball too cleanly. That was a very confident game from Safarova and I think there is a little desperation creeping in for Ivanovic."
Post update
*Ivanovic 5-7 1-3 Safarova
Safarova has not dropped a set so far this year at Roland Garros and it will take a remarkable effort from Ana Ivanovic to take this match into a third. The Serb is not in this contest at the moment, failing to nick even a point as Safarova holds to win her eighth game in the last nine.
Safarova breaks
Ivanovic 5-7 1-2 Safarova*
Safarova springs from defence to attack quicker than a Jose Mourinho football team - she goes a set and a break up! The Czech manoeuvres herself into a position of three break points, taking the second one to draw first blood in the second set. Ivanovic is sinking quickly....
Post update
*Ivanovic 5-7 1-1 Safarova
Gutsy stuff again from Safarova. A break point for Ivanovic is wiped out by another Safarova ace, before the Serb tries to push her opponent behind the baseline and delivers another peach of a forehand to take a second break point. But more brilliant play under pressure from Safarova has Ivanovic looking to the heavens as a return ball dusts the opposite corner of the court to where she is standing. Deuce for the fourth time. Ivanovic looks annoyed as she overcooks a forehand to hand Safarova another advantage - even more so when another ace - Safarova's seventh of the match - whizzes past her eyeline. What. A. Hold.
Post update
*Ivanovic 5-7 1-0 Safarova
A tense Ivanovic spins around in disgust, slapping her thigh too, as she meekly smacks a forehand return into the net for 40-30. The 2008 French Open winner forces deuce in the next point, but sees the break-lined rug pulled from under her feet by a Safarova ace. The Czech cannot convert that advantage though, slapping into the tape from a central position. On we go....
Post update
Ivanovic 5-7 1-0 Safarova*
Ivanovic opens the second set as she looks to hit straight back and end that miserable run of five losing games in a row. No room for the Serb to lose an early break here.
Safarova's forehand winner levels at 30-30 but a flush forehand from Ivanovic eases any lingering tension - as does a crashing ace for the hold. Phew....
Post update
Ivanovic 5-7 Safarova
Piers Newbery
BBC Sport at Roland Garros
"Safarova is on target to break the top 10 for the first time next week, and could go as high as number six if she wins the title. Canadian Rob Steckley has been a driving force behind her improvement - he's the bearded Canadian sitting in her player box and doing a good impression of a surf instructor.
"The former world number 464 is a bit of a character and has worked wonders with Safarova. They clearly get on well."
Post update
BBC Radio 5 live sports extra
Former Wimbledon champion and two-time French Open semi-finalist Jana Novotna: "Lucie looked like she was trying too hard early on, going for too perfect a shot and since she has calmed down she has started hitting the ball more cleanly and finding the angles.
"That is why you have to focus on yourself, there will always been an opportunity to get back into a match and you have to make sure you are able to take it."
Game and first set - Safarova
Ivanovic 5-7 Safarova
Ivanovic is melting in the Parisian sun quicker than an exposed ice lolly. Safarova is not only negating Ivanovic's previously dominant forehand now, the leftie is now controlling the play with her own forehand.
Ivanovic cannot make any incisions in the Safarova serve as the Czech holds to love to take the first set. That was *cliche alert* a real set of two halves....
Safarova breaks
Ivanovic 5-6 Safarova*
Well, well, well. Who saw this one coming? Not me. Seventh seed Ana Ivanovic was coasting towards the first set not too long ago, but in the time it took you to finish your late lunchtime sandwich she is now staring a deficit in the face. Safarova nabs two break points and takes the first one to move within a service hold of the opener.
Post update
*Ivanovic 5-5 Safarova
All square again. The Safarova serve is under the microscope again as Ivanovic, eyes fixed on the high ball, dispatches a drive volley clinically for 30-30. But, not for the first time, Safarova eases the pressure with an ace and then completes the job when Ivanovic misses the target with a forehand.
Post update
Ivanovic 5-4 Safarova*
BBC Radio 5 live sports extra
Former Wimbledon champion and two-time French Open semi-finalist Jana Novotna: "Lucie Safarova has always been a little in the shadow of Petra Kvitova back in the Czech Republic. It is really nice for Lucie to be able to come out and take centre stage. There will be lots of people glued to their televisions back home."
Safarova breaks back
Ivanovic 5-4 Safarova*
When the going gets tough, Safarova gets going! Some gutsy returns from the Czech forces a double break point just when she needs them. One goes begging when a heavy Safarova return flies past the baseline. But then the 13th seed - who hasn't dropped a set at Roland Garros this year - produces a worldy of a forehand return which dusts the final millimetre of the tramline.
Post update
*Ivanovic 5-3 Safarova
Safarova is serving to stay in the first set and, despite coughing up a double fault at 15-0, takes the next three points with relative ease. A forehand winner is followed by a backhand winner, before Ivanovic goes long. But the Serb knows she is now serving for the opening set....
Post update
Ivanovic 5-2 Safarova*
The Ivanovic serve has not really been questioned by 13th seed Safarova - but now it is. The Czech forces deuce, after being 40-15 behind, with a stunning backhand winner. But Ivanovic steps up a gear, luring Safarova into two unforced backhand errors, for the hold. "Come on!" shouts the Serb as we see the first real burst of emotion from either woman.
Post update
BBC Radio 5 live sports extra
Former Wimbledon champion and two-time French Open semi-finalist Jana Novotna: "This is very smart play by Ana Ivanovic, putting top-spin on her forehand into Lucie Safarova's backhand. It is kicking up very fast and high and Safarova is struggling to control it off that wing.
"There have been quite a lot of unforced errors from both players so far. But both are continuing to go for their shots. There are a lot of mistakes, but also a lot of winners."
Post update
*Ivanovic 4-2 Safarova
Piers Newbery
BBC Sport at Roland Garros
"When she emerged on the scene a decade ago, Ivanovic was noted for her heavy, flat forehand and tendency to clench her fist after every successful point. Ten years on and those trademarks are still in place, the fist-clench getting a good workout in a dreamy 10 minutes for the Serb.
"And while not wanting to divert attention to the boyfriend in the crowd, it's remarkable how Bastian Schweinsteiger is able to clap louder than anyone else in a stadium of 17,000 people."
Post update
*Ivanovic 4-2 Safarova
That second break point goes begging for Ivanovic, as the pair continue to trade blows in what could be a pivotal game in this opening set. Safarova hauls herself back from the brink, teeing up two game points of her own, but a classy backhand from the Serb takes us to a third deuce.
Both players are trying to ask questions of the other's backhand - and a long rally ends when Ivanovic's crumbles first. Then Safarova blasts down a quick first serve which is too hot for Ivanovic to handle as the Czech saves a potentially crucial hold.
Post update
*Ivanovic 4-1 Safarova
Safarova is under pressure on her serve again. A second double fault from Safarova contributes to another Ivanovic break point. The Serb can only slam a forehand return into the tape for deuce, but is given another chance when Safarova goes long.
The Czech has found the target with 84% of her first serves - but only 63% have been won.....
Post update
Ivanovic 4-1 Safarova*
Can Safarova build on that morale-boosting hold? In a word...no. Two thumping serves ping off the Roland Garros clay and behind Safarova as a pair of aces give Ivanovic a 40-0 lead following an opening forehand winner. The Czech nabs a point back before grimacing when a backhand return lands inside the tramlines to give Ivanovic the fifth game.
Post update
*Ivanovic 3-1 Safarova
Lucie Safarova needs a comfortable hold here - and that is exactly what she gets. The left-hander wraps up the game in a matter of seconds, thanks to a couple of forehand winners and sloppy Ivanovic returns. Confidence booster....
Post update
BBC Radio 5 live sports extra
Former Wimbledon champion and two-time French Open semi-finalist Jana Novotna on BBC Radio 5 live sports extra: "Lucie Safarova has had a good first serve percentage so far through the tournament and she really has to keep that up because Ana Ivanovic will be all over the second serve.
"She does not really look into the match yet. Ivanovic is keeping her under so much pressure."
Listen live via the audio icon at the top of this page.
Post update
Ivanovic 3-0 Safarova*
Everyone in the Chartier crowd is donning a straw hat - à la the Man from Del Monte (ask your dads) - as the strong sun beats down on Roland Garros. Ivanovic maintains the strong start to her service game, winning four points on the trot after allowing Safarova the luxury of the first point. The Serb is looking composed and extremely confident....
Ivanovic breaks
*Ivanovic 2-0 Safarova
Safarova builds up a 30-0 lead, only to throw that away with an unforced backhand error and a double fault.
That gives Ivanovic hope of an early break and, although Safarova saves with a 171 km/hr ace, a great forehand winner from the Serb sticks her within another point of a 2-0 lead.
This time, she snaffles that chance as Safarova finds the net with a loose backhand. First blood to Ivanovic....
Get involved on #bbctennis and 81111 on text
Who will make Saturday's final?
Freddie Higgs: "So happy for Ana Ivanovic she has played brilliantly and it's time for her to recreate '08"
Kayley Jay: "OK, I've shaken up my magic 8 ball, it says Safarova v Bacsinszky. Asked if it was kidding; reply 'Don't bet on it'."
Post update
Ivanovic 1-0 Safarova*
Ana Ivanovic has the honour of serving first, her first effort lightly dusting the net, before the second is smacked long by the Czech. Ivanovic, decked out in a black dress, confidently sweeps a forehand winner past her opponent before teeing up three game points with a blistering ace.
A brief glimmer of hope for Safarova, who then palms a backhand return into the net. Solid opening hold by Ivanovic.
Post update
Ivanovic v Safarova
Ready? As Jim Carrey would say in The Mask - it's show-tiiiiiime! One last swig of French-branded water for each of these potential finalists before they step up to the clay to a generous round of applause....
Post update
Ivanovic v Safarova
Piers Newbery
BBC Sport at Roland Garros
"Ana Ivanovic has been one of the stories of this French Open, finally breaking back into the final four at a Grand Slam for the first time since she won the title here in 2008. The Serb became world number one that day, staying at top spot for 12 weeks, and it seemed likely she would be battling for the major prizes for years to come.
"However, she had slipped back into the pack of second-week contenders until this week. Roared on by boyfriend Bastian Schweinsteiger, the German World Cup winner, and a team of large and heavily branded men in her support team, the Serb has become a force once again."
Post update
Ivanovic v Safarova
Safarova is the first to emerge into the Paris sun, waving almost shyly to the crowd building up inside Court Philippe Chatrier, before she is quickly followed by Ivanovic. The pair stare across the net at each other for the first time, knocking up before they get down to the serious business of a French Open semi-final.
"Trois minute" says the umpire. That's three minutes until we begin to me and you....
Post update
Ivanovic v Safarova
We catch a quick glimpse of Ana Ivanovic as she prepares to walk out on to a sunny Philippe Chatrier. The Serb, with imaginary racquet in hand, slashes a forehand and then a backhand as she limbers up in the locker room. Then the Serb does some quick on-the-spot sprinting - it is all about the footwork you see. The players are almost ready....
Get involved on #bbctennis or 81111
Who will make Saturday's final?
Adam Nicholls: Serena in straight sets. Ana is 3-5 against Safarova so it will be tough for her to do it. But I am in #TeamAna all the way!
Route to the semi-final
Lucie Safarova
First round: beat Anastasia Pavlyuchenkova 7-6 (8-6) 7-6 (11-9)
Second round: beat Kurumi Nara 6-2 6-0
Third round: beat Sabine Lisicki (20th seed) 6-3 7-6 (7-2)
Fourth round: beat Maria Sharapova (second seed) 7-6 (7-3) 6-4
Quarter-finals: beat Garbine Muguruza (21st seed) 7-6 (7-3) 6-3
Total time on court: 8 hours 31 minutes
Average rank of opponent: 27
Route to the semi-final
Ana Ivanovic
First round: beat Yaroslava Shvedova 4-6 6-2 6-0
Second round: beat Misaki Doi 3-6 6-3 6-4
Third round: Donna Vekic 6-0 6-3
Fourth round: Ekaterina Makarova (9th seed) 75 36 61
Quarter-finals: Elina Svitolina (19th seed) 63 62
Total time on court: 7 hours 28 minutes
Average rank of opponent: 73
Post update
Ivanovic v Safarova
Piers Newbery
BBC Sport at Roland Garros
"The temperature has leapt significantly to the mid-20s today and Roland Garros is bathed in sunshine, apparently for the foreseeable. You know the weather is good here when there are spectators on court before the match actually starts.
"While Goran Ivanisevic and Carlos Moya take on a couple of ball kids in legends' hi-jinx on Court Suzanne Lenglen, the serious business is about to get under way on Chatrier. There are even people in the VIP box already. And not just staff."
Get involved on #bbctennis and 81111
Who will make Saturday's final?
A Scott on text: You're way off with your Ana Ivanovic tip, reckon she will lose worse than Bacinsinszky. A Safarova/Williams final.
Post update
Ivanovic v Safarova
What do you mean you don't know much about Lucie Safarova? Luckily we are here to help.
The Czech leftie is contesting her second Slam semi-final, having lost in the last four to eventual champion Petra Kvitova at Wimbledon last year.
The 28-year-old 13th seed has not yet dropped a set at Roland Garros last year and, of course, beat reigning champion Maria Sharapova in the fourth round.
"She's a great player. She showed that many times. She had a great match against Maria," says Ivanovic.
"It's going to be tough match-up for me. She's obviously lefty, gets really lots of balls back very heavy, very aggressive."
Back in familiar territory
Ivanovic v Safarova
Ivanovic eyes another final
Ivanovic v Safarova
Ana Ivanovic won her first Slam as a 20-year-old at Roland Garros in 2008 - but hasn't really fulfilled her potential since. So understandably she is "very, very thrilled" to reach her first French Open semi-final since 2008.
"It's been a long road and hard work," says the 27-year-old, who was also a Australian Open finalist in 2008.
"Obviously you know seven years ago it was completely different experience. I was a lot younger and I sort of didn't have the experience. I just was so excited and I felt like, you know, I can achieve anything.
"At that point I had so many victories and so many good results. Maybe I didn't appreciate it as much as I do now."
Post update
A gentle hum of excitement can be heard across Roland Garros as the French tennis fans head towards the Philippe Chatrier turnstiles. Hope they have plenty of suncream and protective hats in their bags, the sun is shining and the weather is sweet as Bob Marley would say. About 15 minutes until Ivanovic and Safarova are kicked out of the locker room....
Tale of the tape
Ivanovic v Safarova
Get involved
#bbctennis or 81111 on text
Shake up your magic eight ball. Flip your lucky coin. Give you tea bag a predictive poke.
We are after your predictions today.
Come Saturday afternoon, which two of these four players are going to be dirt-wrestling on the terre battue for the title?
Williams v Ivanovic is your banker I guess, but are there any takers for a Safarova v Bacsinszky showpiece?
Hit us on #bbctennis on Twitter and 81111 on text with your best guesses and reasons why.
Post update
Bonjour mes amis! And welcome to the business end of the French Open - today we are entering semi-final territory.
Four women must squeeze into two final spots.
Either seventh seed Ivanovic or Safarova - the woman who sent reigning champion Maria Sharapova packing - will nab the first one when they meet on Court Philippe Chatrier about 14:00 BST.
And once that match is decided, we will find out if Timea Bacsinszky can cause a shock on the scale of Robin Soderling by beating Serena Williams.
Post update
Honk, honk! Move out of the way ladies - the Serena juggernaut is powering through Paris.
Maria Sharapova has fallen by the wayside.Petra Kvitova has dived out of the way. Simona Halep has been kicked out of the cab.
Williams might not be cruising along in fifth gear at Roland Garros, but the road ahead is wide open and heading straight towards a 20th Grand Slam singles' title.
Can anyone derail the American? Swiss 23rd seed Timea Bacsinszky will be the latest to have a go later today. And if she can't stop Serena then only former French Open champion Ana Ivanovic or Lucie Safarova - who has not beaten the world number one in eight attempts - are the final roadblock.
Post update
Close your eyes, relax and let your mind wander forward to this Saturday.
You may picture Lionel Messi scoring as Barcelona ease past Juventus to win the Champions League final.
You may also visualise Serena Williams collapsing to the Roland Garros clay in celebration. And then being presented with the Coupe Suzanne Lenglen after winning the French Open women's singles title.
Williams, like Barcelona, is the overwhelming favourite to stick her mitts on more silverware this weekend. But, as we know, sport has a habit of throwing up the unexpected....