Hello and welcome to our live coverage of the encounter between former world number ones Novak Djokovic and Roger Federer at the ATP World Tour Finals.

DJOKOVIC 6-4 6-7(2) 6-2 - GAME, SET & MATCH! Djokovic races through a love service hold to secure the win, despite that sloppy second set seized on by Federer. An unreturnable serve seals the match in the end and it is Djokovic who leads Group B after the first round of matches.

DJOKOVIC 6-4 6-7(2) 5-2 - Djokovic is well inside the baseline to drill a backhand return down the line for a winner and level at deuce (just two points away from victory). Federer earns himself another game point though with a much more forceful serve and a forehand volley winner before holding with another great serve out wide - Djokovic will have to serve out this match after the change of ends.

DJOKOVIC 6-4 6-7(2) 5-1 - A clever sliced serve out wide from Djokovic catches the outside of the line to bring up two game points after hawkeye confirms it was an ace. And another unreturnable serve seals the hold that leaves Federer serving to stay in the match.

DJOKOVIC 6-4 6-7(2) 4-1 - BREAK! Djokovic nonchalantly flicks a forehand across court for a winner that lands right on the sideline before going on to earn himself another two break points. The first Federer saves with a brutal rally that ends when Djokovic sends a forehand long. But the Serb secures the double break at the second attempt when Federer pulls a forehand wide aross court to end a 30-shot rally.

DJOKOVIC 6-4 6-7(2) 3-1 - A forehand sent sailing long by Federer squanders the chance to level up at 30-30 and instead hands Djokovic two game points. The first chance goes begging when the Serb nets a backhand drop shot attempt. But an ace down the centre of the court secures the game at the second attempt.

DJOKOVIC 6-4 6-7(2) 2-1 - Federer races through a love service hold in the blink of an eye, sealing the game in one minute and 11 seconds with an ace.

DJOKOVIC 6-4 6-7(2) 2-0 - Djokovic is forced to save an immediate break back point but does so with a speedy trip up to the net to pick up a decent drop shot by Federer. He does require a couple of goes at serving out the game but eventually does so, just as the clock ticks over to the two hour mark, with a forehand approach shot winner across court.

DJOKOVIC 6-4 6-7(2) 1-0 - BREAK! Djokovic really gets up inside the baseline for the opening point of this third set, working Federer from side to side before firing an inside out forehand winner across court to take the first point. He then takes the second and also the third to set up three early break points. Only the one is needed though as Federer slaps a forehand long to concede his serve at the earliest possibility in this decider.

DJOKOVIC 6-4 6-7(2) - SET! Federer only needs the one chance though, lifting a forehand lob high over the head of Djokovic from up at the net. The Serb races back but can only slap his forehand well long as he turns on the shot. This match will go to a third, final set.

DJOKOVIC 6-4 6-6 (2-6) - TIE-BREAK! A huge first serve winner from Federer and a netted forehand from Djokovic hands the Swiss player four set points ...

DJOKOVIC 6-4 6-6 (2-4)- TIE-BREAK! Great stuff from both players but it is Federer who comes out on top with a forehand stop volley winner before taking the mini-break lead at the change of ends when he uses hawkeye to get a call of "out" overturned on a cross court forehand.

DJOKOVIC 6-4 6-6 - A fourth ace from Federer helps him sneak 30-15 ahead before a backhand from Djokovic (off a *very* low slice from Fed) ends up in the top of the net hands the Swiss player two game points. The first goes begging with a netted forehand from up at the net but Federer does hold at the second attempt to force the tie-break.

DJOKOVIC 6-4 6-5 - Djokovic looks to be cruising towards a comfortable service hold to 15 only for back-to-back errors to allow Federer to level at deuce. The Swiss takes full advantage bring up another break point with an attacking forehand but a huge serve out wide from Djokovic saves it. An inside out forehand passing shot winner hands Djokovic a game point which he then grabs when Federer nets a backhand. Fed will have to serve to stay in the match after the change of ends.

DJOKOVIC 6-4 5-5 - BREAK! Djokovic somehow manages to land a return from a blind lunge at the ball, Federer then hitting long to allow the Serb to level at 30-30. One of Federer's best serves of the day so far brings up set point but he goes long with a forehand down the centre of the court to squander it. Djokovic then brings up a break back point with a sensational flicked forehand pasing shot winner. The chance goes begging but the he does break at the second attempt when Fed nets a forehand.

DJOKOVIC 6-4 4-5 - An absolutely brutal serve from Djokovic, nothing Federer could do about that, and the Serb holds without any drama to force his Swiss opponent to serve for this second set after the change of ends.

DJOKOVIC 6-4 3-5 - Federer holds on to his serve this time, albeit not before Djokovic has pushed him to deuce. But a forehand return long from the Serb secures the hold for Federer in the end and Djokovic will have to serve to stay in this second set now.

DJOKOVIC 6-4 4-3 - BREAK! A backhand long from Djokovic after a lengthy rally, followed by another backhand error (his eighth), this time looped wide across court, hands Federer three more break points. Fed only needs the one though as he flicks a forehand passing shot winner across court, the ball catching the net on the way though, although Djokovic would not have got to it either way.

DJOKOVIC 6-4 3-3 - BREAK! A very gutsy second serve from Federer right onto the service line denies Djokovic on an immediate break back point when the Serb is unable to do anything with his return but put it in the net. But Djokovic gets a second chance after a bit of luck when his backhand passing shot attempt catches the top of the tape and bounces up high over Federer's racquet. This time Federer slaps down a double fault to concede the game. All square once again.

DJOKOVIC 6-4 2-3 - BREAK! Djokovic completely mis-hits a backhand, the ball clattering off the frame and landing well wide as the Serb drops the racquet behind his head. Break point Federer. Djokovic saves it but fails to take advantage of a game point when Federer finds the line with a forehand that the Serb can only net. This time Federer does break, Djokovic sending a backhand long down the line

DJOKOVIC 6-4 2-2 - Much, much more emphatic from Federer as he holds to love to level up, working his way into the net and drilling the forehand drive volley across court for a winner to seal the game.