LONDON (Reuters) - Japan's Kei Nishikori made a stunning start to the ATP World Tour Finals with a 6-4 6-4 win over Andy Murray on Sunday but fellow debutant Milos Raonic was put firmly in his place by Swiss maestro Roger Federer.
Asian trailblazer Nishikori walked on court accompanied by the usual O2 Arena music and lights before dismantling home favorite Murray with some dazzling special effects of his own.
Canada's Raonic, like Nishikori the first man from his country to qualify for the ATP's year-ending showpiece, began horribly before improving as he lost 6-1 7-6(0) to six-times former champion Federer.
Federer and Nishikori will now meet in Group B on Tuesday when Murray and Raonic will be battling to keep themselves afloat in the round-robin event.
The 24-year-old Nishikori admitted he tried not to look up into the soaring stands at the 17,000 sell-out London venue in a nervous start against Murray, who qualified for the seventh year in succession after three-title burst since September.
Once the U.S. Open runner-up settled, however, he led former Wimbledon champion Murray a merry dance.
Even a late Murray fightback, when the tenacious Scot battled back from 4-1 down in the second set to 4-4, failed to knock Nishikori off track as he closed out an impressive victory on the electric blue indoor court.
"The stadium is huge. I tried not to look up too much because there was too many people on the top," Nishikori, the world number five, told reporters.
"Maybe when I walked into the stadium, I was nervous, but at the same time I was really excited to play with this crowd.
"I was really happy that I played good tennis on this situation."
Murray broke serve to lead 3-2 in the opening set but immediately dropped his own to love and conceded the opening set in tame fashion when an attempted dropshot nestled into the net.
With plenty of Japanese flags fluttering in the darkened stands, Nishikori quickly forged ahead at the start of the second set, catching Murray well behind the baseline with a cute drop shot to break on the way to a 3-0 lead.
Murray was in danger of being overwhelmed but he 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.
It looked as though it might prove costly for the 24-year-old as Murray clawed back to 4-4 with the help of some Nishikori errors but just when the momentum appeared to have shifted, the Japanese gathered himself for another attack.
He sealed a first victory over Murray in four attempts on his first match point when the Briton wafted a backhand long.
"I didn't serve well enough and he was able to dictate a lot of points, especially behind my second serve," Murray said.
"You need to try to forget about today, work on some things tomorrow, and hopefully play better on Tuesday."
Federer needed only 25 minutes to take the opening set against Raonic.
Despite the Canadian's first serve thundering toward him regularly at over 140mph, the Swiss was unflustered as he twice pocketed Raonic's service games.
Raonic saved a break point at 1-1 in the second set and that escape appeared to fuel him with more belief as his serve and his forehand began to knock Federer out of his comfort zone.
In three consecutive Federer service games the 23-year-old had break points, the last of them being a set point at 6-5.
Federer saved that with a piercing first serve and, crisis averted, rattled through the tiebreaker in quick time.
"The second set was much tougher, it was an important set to win," Federer said on court. "I don't think he played a great breaker but it was a great one to win.
"But we have a tough group so it's always going to be hard advancing but it brings me a step closer."
Editing by Ed Osmond and Steve Tongue