|ATP World Tour Finals, O2 Arena London, 9-16 November|
|Coverage: Afternoon sessions (14:00 GMT) and first semi-final (14:00 GMT) on BBC Two/BBC website, final on BBC Three/BBC website (19:00 GMT); commentary of each match on BBC Radio 5 live sports extra, live text commentary on BBC website|
Roger Federer closed in on a place in the semi-finals at the ATP World Tour Finals with victory over Japan's Kei Nishikori.
The Swiss won 6-3 6-2 and could qualify for the last four on Tuesday depending on the result of the late match between Andy Murray and Milos Raonic.
Federer, 33, needs Raonic to win or Murray to prevail in three sets.
If not, the six-time champion will need to secure his progress in his final Group B match against Murray.
"I'd like to be qualified [today], to be quite honest," said Federer.
"At least then I know I am through rather than having to win a set or maybe having to win the entire match [on Thursday]. I don't even know what it takes.
"Usually if you do win in straight sets twice, things look very, very good."
Asked about his performance against Nishikori, the world number two added: "He's shown in the past when he gets the upper hand against any player from the baseline, he's very difficult to beat.
"Today for some reason he couldn't get it done. Maybe I was playing too well on defence and offence, mixing up my serve good enough.
"But I know that Kei can play better. So for me it was really important to take advantage of the fact that I was feeling really good, and then maybe he was struggling a little bit today."
Nishikori, 24, remains very much alive in the tournament following his opening win over Murray, but he found Federer a different proposition.
An early chance for the world number five came and went in an eight-minute third game as Federer saved a break point with an ace, before Nishikori fired a regulation forehand over the baseline on the second.
Federer grabbed the initiative in the next game with a brilliant cross-court pass and a thumping forehand into the corner to move 3-1 ahead, and he never looked back.
Nishikori is a great ball striker and one of the best movers in the game, but his lack of punch on serve allowed Federer to keep the pressure on when returning, and only a sharp backhand volley prevented the Japanese player going two breaks down.
Federer saw out the set with little fuss and there was a sense of inevitability about the forehand error that saw Nishikori drop serve early in the third.
As his first-serve percentage fell below 50% and the error count increased, Nishikori double-faulted for the fifth time to hand Federer a 5-2 lead.
The world number two saved break point on his way to closing out the match after 67 minutes, and it is now highly unlikely he will suffer only a second group stage elimination in 13 appearances at the season finale, when he takes on Murray on Thursday.