Roger Federer wins 7-5 6-2 in London
Federer into semi-finals with second win
Swiss leads head-to-head 22-21
Both won their opening group matches
Miles Maclagan
British tennis coach on Radio 5 live sports extra
Quote MessageThe style of tennis Federer plays means they bring out the best in each other. Djokovic's ability often goes understated - look at how he pegged Federer back there. That's why Federer respects him so much.
Djokovic breaks
What a match. Djokovic isn't a man who will give up lightly. The Serb collects two break back points. Federer erases one with a classy serve. But the Serb's defence is impenetrable on the next point, Federer rushes a forehand, wide it goes. Talk of Djokovic's demise has been greatly exaggerated.
Image source, Reuters
Piers Newbery
BBC Sport at the O2 Arena in London
He's been up on his feet in ecstasy, he's had his head in hands in misery - and that was just the first game. Federer's overwhelming popularity comes as no surprise but one gentleman a few rows in front of me has been living every point of this. Meanwhile, Swiss chants boom out from the clumps of red visible in the darkness. The O2 is hosting the Federer show once again.
Federer breaks
Federer, who takes a 0-15 lead, has won 15 of the last 20 points. Make that 16 as Djokovic's forehand malfunctions once more. The Serb has stumbled upon difficult times. Federer supreme, bullying the world number one. Djokovic into the tape and the six-time champ has three break points.
A serve out wide, a forehand into the same corner. One break point saved. A canny second serve, catching Federer unawares and the Swiss nets the return. Two break points saved.
A sliced return from Federer... Djokovic unsteady on his feet... scooping... wobbling... and his backhand volley goes into the tape.
We go again. Hopefully these two will be going all night long. Federer wrong footing Djokovic with a canny forehand. It's not often the Serb is tricked in such a way. A1 defending from Federer for a routine hold.
Image source, AFP
Sara Orchard
Radio 5 live sports extra commentator
Quote MessageThese guys are serving up an early Christmas present here. It's a cracking contest.
Miles Maclagan
British tennis coach on Radio 5 live sports extra
Quote MessagePerfect tennis from both players and Federer with the deftest of touches drops it over the net to win the point. It needed that magic to break the deadlock. Boy, what a match this is. The standard of tennis is of the utmost quality.
Djokovic 5-7 Federer
Another ace from Djokovic. That's one way of stopping the rot. Federer, though, a geometric delight, finding zany angles all over the court, posing questions, and not even a man of Djokovic's steel can hold firm in such circumstances. Deuce. Second Set point. Ear-drum rattling roars.
Bravo! Federer on the front foot, working Djokovic this way and that, before producing a breathtaking volley which dramatically kisses the line. The Swiss forms a fist. The crowd yell their approval.
Beautiful. A mammoth baseline battle... the pair trade blows... 22 shots, 23 shots, and it's Djokovic who stumbles, chucking a forehand beyond the baseline. 15-15.
A beefy serve nudges the Serb ahead. Plenty of variety in the Serb's arrows, slicing, dicing... But Federer, undeterred, is bold and brave, coming into the net and, once again, Djokovic falters. Long once more. 30-30. A chance.
My, my, my... Djokovic drags a forehand into the tramlines. It seemed routine. Set point Federer. The Swiss blows his fingertips with the crowd's roar ringing in his ears...
They're rooted to the baseline on the next point. And Federer slaps a forehand into the tape... deuce...
Who will win?
Paul Staveley: Both these legends bringing their A game -should be a real ding dong here! They have a class that separates them from all others.
Miles Maclagan
British tennis coach on Radio 5 live sports extra
Quote MessageThey have whizzed through these games with some clean serving, apart from the one break point chance Federer fended off in his opening service game.
Classy from Federer. The Swiss produces his most confident service game in squeaky-bum time. A hold to love and it seems as if this set will be decided in a tie-break.
Image source, Getty ImagesThe O2 spectators turn up the volume as Djokovic bounces a few balls onto his racquet. He's waiting for the din to quieten before he serves. Federer showing ambition, attempting a curling forehand winner which drops long. 30-15.
A first double fault for Djokovic. Former England wicketkeeper Alec Stewart, sitting near Boris Becker, quietly looks on while a few spectators gasp at the Serb's error. 40-30.
A gettable serve for Federer... his eyes widen... adrenaline pumping... but he's wild and loose with the return. Opportunity missed.
A swing of the hips from Federer on the opening point, the Swiss hitting loose and free with a thunderclap of a forehand. He then closes with a stonking backhand winner down the line. Two thigh-slappingly good shots bookends to fabulous serving.
There's yet to be a truly magical baseline slug-fest or jaw-dropping exchanges of volleys because both men have been serving with such aplomb. Djokovic lasers an ace towards his rival for a 40-0 advantage, an unreturnable second-serve down the 'T' seals the deal. It's all quite beguiling in an unspectacular sort of a way.
Image source, AFPMiles Maclagan
British tennis coach on Radio 5 live sports extra
Quote MessageFederer has had some good serves which have dug him out of trouble while Djokovic is getting a slight upper hand at the baseline. We've seen these two play 42 times so there won't be any surprises how they play - it's all about who can take their break points.
Who knows which way this match will swing. The pendulum currently tree trunk still, unwilling to swish in favour of either side. Federer upping the ante, threading a fabulous down-the-line winner to gallop to 40-15.
Djokovic unable to cast his spell from the baseline because the Swiss is serving with such unnerving accuracy.
Djokovic testing the Federer backhand, bash, bash, bash, crosscourt to crosscourt... but the Swiss is holding firm and it's the Serb who falters, sending a forehand long.
Federer the more prepared of the two to gamble, to throw the dice, which he does when with a feather-soft dropper which curls onto the paint. Djokovic sprints in an attempt to retrieve but volleys into the tramlines. 15-30. Volume lifts inside the O2.
Djokovic, though, as calm as a cucumber wrapped in an ice pack. He hits cleanly from the baseline, the forehand is his friend now, and comes through with distinction.
Federer oozing confidence as he arrows a boomer of an ace down the middle for a 40-0 lead. Just as in Federer's previous service game, though, Djokovic claws his way back into contention - a dazzling winning return for 40-30. But Federer simply unleashes another ace to nip the comeback in the bud.
Image source, AFPThe 02 crowd have been more vocal, they're currently too transfixed on the game's greats to burst into any sort of song. Djokovic content to remain on the baseline, occasionally stepping a foot or two in to crunch home a forehand winner. He proceeds to 30-0 with ease. Federer unable to truly test the world number one, a forehand long, Djokovic to 40-0.
A screwed backhand into the tramlines the only error from the Serb before he serves out wide to comfortably hold.