Kei Nishkori
Nishikori staged a comeback in the second set but was unable to defeat Federer.Getty Images

Kei Nishikori is out of the ATP World Tour Finals despite twice coming back from the brink in his three sets loss to Roger Federer at the O2 Arena in London. The former US Open finalist needed to win to keep his semi-final hopes alive, but Federer prevailed 7-5 4-6 6-4 to top the Stan Smith group after ousting the Japan right-hander, who recovered from a break down in successive sets before eventually being defeated.

The result means three-time defending champion Novak Djokovic needs just one set against Tomas Berdych to join Federer in the last four. The Czech can only progress with a two-set win over the world number five – a result he has achieved just once in the pair's 22 career meetings.

Despite having already earned a place in the knock-out phase, the six-time champion Federer showed no signs of letting up in the opening exchanges. The Swiss stormed into a 3-1 lead but was dragged back by Nishikori amid a run of four breaks in five games.

Three straight holds followed before the nervy Nishikori blinked first as Federer grabbed a set point and the advantage. The blow did not change what was required of the Japan number one, yet his challenge became all the more daunting when Federer opened up a 4-1 lead in the second set.

Nishikori's upped his intensity however and reeled off five straight games to overwhelmed Federer and level the match, while resuscitating his semi-final hopes. All the momentum was with the Japan number one but he failed to take three chances to break in game three of the decider as Federer kept his nerve.

Federer piled on the misery for Nishikori by seeing off a game point to break for a 4-1 lead in the third set, to leave his opponent on the brink for a second time. But Nishikori naturally responded, creating two break point chances, the second of which saw Federer send a forehand long.

An untimely double-fault saw a game point come and go for Nishikori when faced with serving to stay in the tournament and it was a window of opportunity that Federer would not scupper. The world number three hit a fine overhead volley to claim a third straight round robin win and send Nishikori packing.