Roger Federer eased his way into the ATP World Tour Finals with a 6-1, 7-6 (0) defeat of Canadian newcomer Milos Raonic in his opening round-robin match on Sunday.
The 33-year-old Swiss, competing for a record 13th time at the season-ender, took advantage of some early Raonic nerves to pocket the opening set in 25 minutes but things got tougher.
Raonic, the first Canadian to qualify for the tournament, began to do damage with his booming serve and even carved out several break point opportunities as world number two Federer's level dipped slightly.
Six-times champion Federer saved a set point at 5-6 and that proved to be Raonic's last chance.
Federer quickly asserted himself in the tiebreak and reeled off seven successive points to move top of Group B alongside Japan's Kei Nishikori who had earlier beaten Andy Murray.
"I think I played really well for probably one and a half sets," Federer, who has progressed to the semi-finals in 11 of his past 12 appearances at the year-ender, told reporters.
He admitted things got a little tricky after he failed to establish an early break of serve in the second set.
"I think when I had breakpoint in the second set, he was able to save that and after that it became complicated. I don't know why.
"I started to play a bit more passive. He started to become a bit more offensive. I actually think he was the better player from that moment on and deserved the set more than I did."
Federer now moves on to play Nishikori while Raonic will probably need to beat Murray to keep his hopes of surviving the group stage alive.
"I get pretty angry when I lose, so ... I'm going to have to learn how to slap myself out of it," said Raonic, who had beaten Federer for the first time in the recent Paris Masters.