Nishikori powers to victory over Murray at Tour Finals

Japan's Kei Nishikori made a stunning start to what will surely be the first of many appearances at the ATP World Tour Finals with a 6-4, 6-4 win over home favourite Andy Murray on Sunday.

The opening group match of the elite season-ender began slowly but once world number five Nishikori found his range he dominated the twice grand slam champion in front of a sell-out crowd at the spectacular 02 Arena.

U.S. Open runner-up Nishikori battled back from dropping serve in the fifth game of the opening set to break world number six Murray twice -- the second time when the Scot netted an ambitious drop shot to gift his opponent the set.

With plenty of Japanese flags fluttering in the cavernous arena, debutant Nishikori quickly forged ahead at the start of the second set, catching Murray miles behind the baseline with a cute drop shot to break on the way to a 3-0 lead.

Murray scrapped and scraped his way through his next service game when Nishikori failed to take three chances for a 4-0 lead, one of which, a missed forehand down the line, was a glaring error from the Japanese.

The 24-year-old Nishikori, who has enjoyed a year of landmarks for Asian men's tennis including becoming the first man from the continent to qualify for the Tour Finals, refused to loosen his grip and held for a 4-1 lead.

Never is Murray more dangerous than when his back his firmly up against the wall, however, and the former Wimbledon champion nagged away long enough to encourage some errors from Nishikori.

Twice the Japanese player netted volleys in the seventh game and suddenly the set was back on serve.

The momentum appeared to have shifted Murray's way but Nishikori gathered himself for another attack and sealed a first victory over Murray in four attempts on his first match point when the Briton wafted a backhand long.

Later in Group B, six-times former champion Roger Federer takes on Canadian newcomer Milos Raonic.