2210: So that just about wraps up our coverage of the ATP World Tour Finals semi-finals. One was an absolute belter of a match, the other a cold-blooded demolition. It leaves us with the tantalising prospect of Rafael Nadal and Roger Federer scrapping it out for the 22nd time in Sunday's final; the latest instalment in one of the greatest rivalries the sport has ever seen. Kick-off is 1730 GMT and you really, really don't want to miss this one. Really. See you then. Oh, and in the meantime, you can relive Federer-Djokovic via Piers Newbery's match report. Night.

Times tennis correspondent Neil Harman on Twitter: "I only hope Rafa recovers physically from the ultra-demanding semi v. AM. If so, a final to savour. They last played 5 mnths ago in Madrid."

BBC Sport's Piers Newbery tweeting from the O2 Arena: "Federer finishes off NoDjo 6-1 6-4 after 79 minutes and looks like the favourite to me now. Federer v Nadal in the final. Tasty."

2151: "It seems like it's working this week," says Federer following his victory. "I played well against a player who's had a great season. I played a great match so I'm very happy. I hope I can keep this up for a long, long time. I'm really enjoying myself and I hope I can produce something good tomorrow. Rafa showed today why he is the best player in the world at the moment and it should be a good match. We haven't played that much recently but I'm looking forward to playing him. Our styles match up well and he's always very respectful, which I appreciate. We've had some epics and some matches that didn't quite live up to expectations. Hopefully tomorrow will be a great match."

Federer 6-1 6-4 Djokovic
Text book front foot cover drive (this is cricket, isn't it?) puts Federer 15-0 up. When Djokovic goes long it's 30-15 and a forehand wide makes it 40-15. Two match points. Djokovic frames a forehand return into the crowd. That's it. Game, set and match Federer. Still hasn't dropped a set all tournament. No smiles from Federer - his mind is firmly set on Sunday's final against Rafael Nadal. The final everyone wanted. Nadal v Federer at 1730 GMT. Can't wait.
* denotes NEXT to serve

Federer* 6-1 5-4 Djokovic
Wonderful from Federer. The world number two drills a forehand down the line that Djokovic volleys into the net at full stretch. He then runs round a second serve to punish his opponent with a forehand winner. A ruthless drop volley takes the Swiss to 40-15 and two break points. He nets a backhand first up there will be no mercy at the second time of asking. Second serve... Federer runs round and dispatches another forehand. Take note, kids.
* denotes NEXT to serve

BBC Sport's Piers Newbery tweeting from the O2 Arena: "Sir Ian McKellen and Elaine Paige in the crowd tonight - John Barrowman presumably busy. Djoko battling hard now, 4-4 in the second set."

Federer 6-1 4-4 *Djokovic
Djokovic nets a forehand to get things going but bounces back with a backhand winner down the line. Federer re-takes the initiative for a crisp forehand but Djokovic responds in kind and we're at 30-30. Some tennis of the highest order taking place out there right now. A slight lapse in concentration sees Djokovic net a forehand, only for Federer to flash one long. Deuce. Djokovic's support team on their feet, will their man on. Federer aces the Serb to bring up game point, and he gets over the line with an unreturnable.
* denotes NEXT to serve

getalex on Twitter: "My girlfriend's hijacked the TV to watch X-Factor...meanwhile, Fed's back in form and I'm missing it."

Federer* 6-1 3-4 Djokovic
A sliced overhead takes Federer to 40-0 on the Djokovic serve and that means three break points. Some monstrous hitting sees Djokovic save the first two before a well-placed forehand winner extinguishes the threat. Federer then slices a backhand return long but gets his act together with a crosscourt forehand winner. Djokovic looks to be in trouble when an overhead is called out but he challenges and Hawk-Eye backs the Serb - his smash kissed the line. Federer this slices a return into the net to hand over the game.
* denotes NEXT to serve

Federer 6-1 3-3 *Djokovic
In the blink of an eye, Federer is 40-0 up. Looks to close out with a serve-forehand combination and he pulls it off. Djokovic motionless on the baseline. Federer bounces on his toes. "He looks in the mood again; he went into his shell but he's just exploded out again," says Jonathan Overend on BBC Radio 5 live sports extra.
* denotes NEXT to serve

Federer* 6-1 2-3 Djokovic
Curling forehand winner from Federer prompts a collective "woah" from the spectators. A long forehand gives Djokovic 30-15 but a masterfully-constructed point from Federer then ends with the world number two wrong-footing his opponent for 30-30. Djokovic then shoves a straightforward forehand volley beyond the baseline and Federer has a break back point. Thrilling rally ensues and Federer comes in. Can Novak pass him? The Serb tries a semi-lob but it floats long and wide. Federer breaks back and returns to his chair with a skip. Coach Paul Annacone delighted in the stands.
* denotes NEXT to serve

Federer 6-1 1-3 *Djokovic
A strange forehand crosses the net and dies to give Federer 30-0. When Djokovic stops running in the next rally it's 40-0. Federer miscues a backhand into the crowd but normal service is resumed with a forehand winner down the line. How will Novak respond?
* denotes NEXT to serve

Federer* 6-1 0-3 Djokovic
Federer looks to put some immediate pressure on the Djokovic serve and moves to 30-0. But a superb pick-up - with the aid of a net-cord - start the fightback. A couple of Federer errors give Djokovic game point and he consolidates the break when Federer lashes a backhand wide. A little show of frustration as Federer heads to his chair.
* denotes NEXT to serve

Federer 6-1 0-2 *Djokovic
A backhand return sails long to give Federer 30-15 and the Swiss moves to game point with a rasping off-forehand winner. But a late flurry from Djokovic sees the Serb plant two forehand beyond Federer and we're at deuce. And here's a crosscourt forehand return... winner. Break point to Djokovic. In comes Federer on the chip 'n charge... but he dumps his volley into the net and there's the break. It's like the first set all over again but with roles reversed.
* denotes NEXT to serve

Federer* 6-1 0-1 Djokovic
Solid start for Djokovic, a hold to 15 with some really aggressive forehand and an overhead that nearly took the felt off the ball.
* denotes NEXT to serve

2100: Would be great to see Nadal v Federer in a final again. To think between them they have won 25 out of the last 30 Grand Slams. Total domination."
Justin in Birmingham via text on 81111

katemortmain on Twitter: "I'm a TV-less Federer fan who couldn't survive without your updates! Go Roger!"

Federer 6-1 *Djokovic
Two drive volleys put Federer in command and when Djokovic twice miscues forehands, the players are walking towards their seats. Federer wins the first set and this is turning into a demolition in the purest form of the word. Djokovic isn't even playing badly. It's just Roger is on absolute fire.
* denotes NEXT to serve

Federer* 5-1 Djokovic
Shaky couple of points from Nole. A lob lands beyond the baseline, a double fault arrives at a terrible time and a backhand flies long. Three break points to Federer. The reigning Australian Open champion goes long on the first and nets both the second and third to take us to deuce, but a gorgeous forehand winner brings up a fourth break point. This time the Fed Express makes no mistake. He spots Djokovic racing into the net, drills in a body shot and watches on as the world number three next his volley. Federer gets the double-break.
* denotes NEXT to serve

SamadGigii on Twitter: "Roger's forehand is looking ominously good so far! Allez Roger!"

Federer 4-1 *Djokovic
A murmur from the crowd as Federer gets us up and running with a double fault, but he's back on level terms thanks to a netted backhand by Djokovic, who then swerves a backhand wide. Federer is similarly profligate with a forehand before Djokovic loops a forehand long. The 23-year-old challenges what was a late call but Hawk-Eye shows it was indeed long. Federer nets an attempted pass for deuce but an ace takes him to advantage. There's no let-up from Djokovic, though, and a well-constructed points ends with the world number three running round for a forehand winner. And here's a second serve... Djokovic nets. Bad miss. Inside-out forehand winner and the Fed fans are on their feet. Important hold.
* denotes NEXT to serve

Federer* 3-1 Djokovic
Djokovic springs out of his seat before umpire Steve Ulrich has even called times. And the Serb starts like a train. But Federer's taking his opponent out of his comfort zone and the Serb shanks a forehand well wide. Djokovic gets to game point but Federer finishes a lengthy rally by stepping in and drilling a backhand winner down the line. Glorious from the Swiss. Djokovic shakes his head in disbelief. The world number three mockingly raises his arms in celebration when Federer mishits a forehand and then throws down an ace to get his name on the scoreboard.
* denotes NEXT to serve

Federer 3-0 *Djokovic
Surely Federer can't maintain this level. Yes, Nadal and Murray drew gasps from the crowd earlier but this is something else. The world number two races to 40-0 with the help of a serve-volley and the most majestic half-volley pick-up at the net. Djokovic replies with a pass and Federer miscues a forehand. But when Novak nets a routine volley, the scoreboard is beginning to look terribly one-sided.
* denotes NEXT to serve

Federer* 2-0 Djokovic
Serbia's finest gets going with an ace before the Fed Express replies with a well-disguised drop. The Swiss then fires forehands long and wide. Djoko is the next to attempt a drop shot but he can only find the net and when Federer plants a volley into the far corner we're at deuce. A gripping rally ends with Novak pushing a forehand into the tramlines and it's break point Federer. Double fault. Federer breaks and deservedly so. The Swiss is stirring, Djokovic wobbling.
* denotes NEXT to serve

Federer 1-0 *Djokovic
After winning the toss and opting to serve, Federer opens with a faultless hold to love. An ace and a forehand winner to seal the deal, the world number two gets his nose in front early doors.
* denotes NEXT to serve

BBC Sport's Piers Newbery tweeting from the O2 Arena: "Federer & Djokovic stroll into the arena as calm as you like. Live text & 5live sports extra under way. Rog in two..."

2022: Fed and the Djoker out on court knocking up as we speak. Rather loud ovations for both men. Roger in his red top and matching bandana, Novak in that dark blue and red number with fancy dragon-like patterning. Who we going for, Roger? Novak? On the fence, me.

2020: Surely everyone is cheering for Fed today. There would be no better way to end the season than a battle between the great Nadal and the even great er Federer!"
Anon via text on 81111

2017: "I'm happy to be here once again," says Federer, who won all three of his group matches - against David Ferrer, Murray and Robin Soderling - in straight sets. "I lost against Davydenko last year which was a pity." On playing Djokovic, the world number two adds: "We've played a lot - there is no secrets. It's important for me to play my shots and go for it so we'll see what happens."

2015: "I'm a student at uni with no tv license! Relying on your online updates to see me through yet again! Hoping for a Fed win tonight!"
Megan in Bath via text on 81111
Refreshing honesty

2012: "It will be a challenge to play Roger," says Djokovic, who started with victory over Tomas Berdych on Monday and then lost to Nadal before beating Andy Roddick. "I expect a tough one but I will give my best. The small details will probably decide the winner."

2010: The doubles is done and dusted so Roger and Novak should be with us shortly. World number two Federer, a 16-time Grand Slam champion, leads the head-to-head 12-6 and has won their last two meetings, in Shanghai and Basel. But at this year's US Open it was world number three Djokovic who came out on top to, yes, set up a final against Nadal. Federer is bidding to equal the record held by Ivan Lendl and Pete Sampras of five end-of-season championships titles and this is his eighth semi-final. Serbian Djokovic's mind may be trained on next week's Davis Cup final against France in Belgrade, but his form in London has been superb.

2005: You can't all be out on the town tonight, can you? Hope not because I'm relying on you to get involved in this very text commentary. Yes, YOU. And this is how to do it - Tweet me @bbcsport_david, text in on 81111 (UK) with TENNIS before your message, or dip into the 606 messageboards. It's an order.

2000: If the day's opening semi-final is anything to go by, we should be in for a belter. Nadal was pushed all the way by Andy Murray but showed all the qualities of a world number one to come through and keep himself in the hunt for a maiden end-of-season championships crown. We're just waiting for a doubles match to finish, then we'll be under way with Federer-Djokovic.

1955: Saturday nights in London were made for moments like these. Roger Federer v Novak Djokovic in the semi-finals of the ATP World Tour Finals at a 17,500-capacity O2 Arena. The prize? A best-of-three sets meeting with Rafael Nadal for the right to take home an extremely handsome cheque, shed loads of ranking points and the very last title of the season.