The second-ranked Swiss lost the first set but still managed to beat Marin Cilic 6-7 (5), 6-4, 6-1 at the ATP Finals on Thursday.
“It wasn’t easy,” Federer said. “I mean, look, it’s a fast court. It’s indoors. We’ve seen it now: When you miss a few too many opportunities you can really pay the price at this tournament.”
The outcome didn’t really matter, though. Federer had already advanced to the semifinals at the season-ending tournament by winning his opening two matches at the O2 Arena, while Cilic had already been eliminated.
In the late match, Jack Sock will face Alexander Zverev for another spot in the semifinals.
Federer, who beat Cilic in straight sets in the Wimbledon final in July, had four break points in the first set on Thursday, but he couldn’t convert any of them. That allowed Cilic to take the lead when he landed a backhand drop shot and then a forehand to close out the first-set tiebreaker.
Federer had another break point early in the second set, but he again failed to convert. But his sixth attempt was different and winning it gave Federer the second set.
In the third set, Federer broke early and jumped out to 3-0, and then broke again to lead 5-1.
“In the beginning, I was slightly overaggressive in the first set on some crucial points rather than maybe being patient,” Federer said. “I was able to turn that around late in the second set. Then just had a much better feeling in the third set.”
Cilic is ranked No. 5 in the world — achieving a goal he set for himself at the end of last season.
At the ATP Finals, however, the Croat has won only once in nine matches over three appearances at the round-robin tournament.
“Overall, I felt that my level has come to a new level,” Cilic, the 2014 U.S. Open champion, said of his 2017 season. “So hopefully even more next year, I can aim a little bit higher. Where is that going to be? I’m not sure. But hopefully, I’m going to be in a position to challenge the top guys and to be in contention for Grand Slams.”
In the semifinals, Federer will face Dominic Thiem or David Goffin. Both have 1-1 records in the other group and meet Friday to decide which player will advance along with Grigor Dimitrov.
Federer, the 19-time Grand Slam champion who won his record eighth Wimbledon title, is looking to extend another record for titles at the ATP Finals. The 36-year-old Swiss has won it six times; twice in Houston, twice in Shanghai and twice in London.
Federer has reached the semifinals at the ATP Finals 14 times and has finished the round-robin stage unbeaten 10 times.
Regardless of the outcome in London, Federer will finish the year ranked No. 2 — behind Rafael Nadal.
“I’m so happy that I was able to reach this level of play and still be able to play also at the end of the year,” said Federer, who also won the Australian Open this season. “I have no regrets because I totally over-exceeded my expectations. Just happy I’m injury-free and healthy right now, enjoying myself still.”