Nishikori edges Ferrer

Djokovic wastes little time in sinking Wawrinka

Japan's Kei Nishikori surged to a three-set victory over alternate David Ferrer at the ATP World Tour Finals on Thursday and must now wait anxiously to see if he has done enough to reach the semi-finals.

The 24-year-old lost the opening set to the Spaniard, who was a late stand-in for injured Milos Raonic, but played beautifully after that to seal a 4-6, 6-4, 6-1 win — his second in Group B after also beating Andy Murray.

The result was enough to guarantee six-times champion Roger Federer a place in the semi-finals even before the Swiss walks on court to face home favourite Murray in the evening session.

Should Murray win in straight sets he would top the group, but any other result would send Federer through as group winner with Nishikori runner-up and the Scot packing his bags.

Near sell-out crowds at the O2 Arena had not been treated to a three-setter at the tournament before Thursday's action but when Ferrer stepped in for a brief cameo role the likelihood was that the gritty 32-year-old would provide one.

Ferrer, beaten in nearly three hours by Nishikori in the quarter-finals of the Paris Masters, a result that scuppered his hopes of qualifying for the year-ender by right, hit back from a break down to take a high-quality opening set.

From then on, however, US Open runner-up Nishikori showed why he has become a trailblazer for Asian tennis, unleashing his full repertoire of fiercely struck groundstrokes and silky drop shots to run Ferrer into the ground.

After converting his first set point in the second set with a backhand winner, Nishikori raced ahead in the decider against a tiring opponent who will return home around $160,000 richer for his brief appearance in London.

Djokovic excels

For 15 minutes Novak Djokovic appeared to have a fight on his hands at the ATP World Tour Finals on Wednesday, then the Serb dialled up his A game and tore Stanislas Wawrinka to pieces.

Such was the perfection of his tennis for most of a 6-3, 6-0 thrashing it is hard to argue against him crowning his year as world number one and with a hat-trick of titles at the ATP's year-ending showpiece.

The 27-year-old has conceded only five games so far at the O2 Arena yet the arithmetic of round-robin tennis means the seven-times Grand Slam champion is still not definitely assured of a semifinal spot.

Even more bizarrely, US Open champion Marin Cilic, crushed 6-3, 6-1 by Czech Tomas Berdych in the day's earlier Group A match could conceivably scrape through despite two heavy losses.