Lucie Safarova to get us going and she lands with a feisty first serve and follows up with a deep forehand that Williams cannot claws back. The purple patch continues and Safarova is 1-0 up.

Wow. Wow. Wow! Put your hands up if you saw this one coming? Me neither. Safarova pulls a rabbit out of the hat - or a neat forehand winner down the line to be more precise - to break the Williams serve. Tie-break time!

Image source, Getty Images

Earlier we saw Andy Murray unable to maintain such a high level of concentration after drawing level with Novak Djokovic - and it looks as though the same has happened to Safarova.

The Czech wrestled her way back into this contest brilliantly, but the mental and physical exertions of wiping out that double break back have now hit her like a Serena-shaped juggernaut. The 13th seed cannot cling on to her serve, cheaply hitting a pair of long returns before the American pulls a backhand winner right out of the top drawer to take the game.

One more service hold and Williams is the Roland Garros champion for a third time...

Serena - that's one euro in the swear box please. The American loses her cool, turning the Parisian air blue, as she hammers a second serve past her opponent for 15-0. Another yelp follows as she slams down her eighth ace of the match to draw level again in this remarkable second set.

Image source, Getty Images

Rich P:, external And so it begins...The unthinkable?

Former Wimbledon champion Jana Novotna on BBC Radio 5 live:

"This is absolutely amazing - so many double faults creeping into Serena Williams' game. In every match you always get a chance, a little opening to get back into the match. It is all about Lucie Safarova trying to take that now."

Miles Maclagan
Former coach to Andy Murray and Laura Robson on BBC Radio 5 live

"It is quite remarkable - five double-faults in two games from Serena Williams. The situation has got to Serena and there are more unforced errors, she is not hitting the ball as cleanly and suddenly Lucie Safarova has a little more time on her shots. She is well and truly in this match."

Image source, Reuters

That old rogue Mo Mentum has sloped away from Serena Williams and is now cosying up to Lucie Safarova on the opposite of the court. The Czech clambers out of a potentially sticky spot at 30-15 to hold serve and heap the pressure back on to her illustrious opponent.

That is four games on the bounce for the 13th seed as Williams serves to stay in the set...

Oooh, there is another glimmer of hope flicking across the red Roland Garros clay and into Safarova's sight. The Czech leads 15-0, and then 30-15, when she entices Williams off the baseline and into a pair of heavy returns. Williams looks a touch rattled. The pair become embroiled in a long rally, which ends when Serena spoons a double-handed backhand into the depths of the tramlines. Two break points...

And Safarova needs just the one! Again Williams is her own worst enemy, introducing another double fault to the Czech's side of the scoreboard. Well, well, well...

Image source, Reuters

Imagine if Safarova handed that break straight back. Just imagine. Not a chance! The Czech wakes up the Paris crowd with a comfortable hold - they don't want to go home yet. Can Safarova find another chink in the Williams serve? (Or, more accurately, will Williams's serve spontaneously combust again?)

Former Wimbledon champion Jana Novotna on BBC Radio 5 live:

"It is something to hold onto and Lucie will take anything at the moment. Those two double faults are a big present from Serena."

Image source, Getty Images

Williams has already accelerated down the back straight, she has rounded the bend and is now eyeing up the finish line.

Oh, hang on. Someone has ran onto the track and stick a hurdle in the way. Williams rattles through the first point but gives Safarova hope with a double fault. Then, follows that up with a 120mph ace.

But the American has another meltdown. First she slashes into net for deuce and then cooks up two rotten double faults to give Safarova hope. Little hope, but hope nonetheless.

Le Millenium: , externalSerena is the greatest of them all... It's a privilege to witness her success. A true champion

Somebody call the brass band and get some banners made quick - that's all we need to complete this procession. Williams is marching towards a third Roland Garros title. Safarova puffs her cheeks out, almost resigned to her fate, as a backhand winner gifts a break point to Williams. And the American pounces on it like a hungry cheetah, swatting a hefty backhand towards the back of the court.

Image source, Getty Images

Image source, Getty Images

I'm running out of superlatives here. Williams is simply imperious. That's a sick and unwell Williams, don't you forget. The American lets out a loud grunt as she puts everything behind a brutal backhand winner down the line to regain her advantage. I've barely got the energy to nip to the shop across the road when I'm ill, never mind smash an opponent all over the tennis court. In 22C heat.

Rich P: , externalBreak of serve first game of 2nd set and match already as good as over. Serena certainly has her 'game face' on today. Immense.

Respite for Safarova, who will be delighted to look up and see her side of the scoreboard grinding into action. The Czech tries to get Williams moving across the baseline, which she does to a degree of success, clinging on to the hold. But she is still a break down remember....

Image source, EPA

Former Wimbledon champion Jana Novotna on BBC Radio 5 live:

"Serena has been so dominant today it is not that Lucie is not playing badly or is nervous. She has just been overpowered by Williams who has been playing so well.

"The one thing I would like to see Lucie do is try the serve out wide more to get Serena moving more and further out of court. She just has to stay positive and hope to spot an opening, a chance to switch the momentum in this match."

Safarova isn't playing badly - she just isn't playing at Williams' level. Remarkable power and poise from the world number one as she rattles off a service hold in a matter of seconds.

Image source, Getty Images

There are no clouds in the electric blue Paris sky - but if there were then they would be hovering ominously over Lucie Safarova. The Czech manages to keep Williams at bay in two break points, but has no answer on the third when the American powers a forehand winner past the hapless Safarova.