Kei Nishikori stuns Roger Federer in ATP Finals opener

WATCH— Kei Nishikori tops Roger Federer in London:

Kei Nishikori beat Roger Federer for the first time in more than four and a half years on Sunday, snapping a six-match losing streak to the Swiss with a 7-6 (4) 6-3 round robin win at the ATP Finals.

The two players held tightly to their serves early on, with neither player even facing a break point in the first 12 games of the match - Nishikori was the one who pounced in the first set tie-break, though, storming out to a 6-1 lead and eventually closing it out four points later to take a one-set lead.

WATCH—Federer speaks to the press after his loss on Sunday:

Federer struck back in the first game of the second set, bringing up triple break point—the first break points of the match—and breaking for 1-0, but Nishikori broke right back and eventually got another crucial break for a 4-2 lead. The two men held from there until the Japanese served out the victory.

“I’m glad to win today. It’s never easy to play with my idol,” Nishikori said in his on-court interview. “Obviously the first match isn’t easy - we both struggled a bit, first set especially - but in the second set I was playing better. It’s always a big challenge playing Roger and it was great to win today.”

Nishikori hadn’t beaten Federer since Miami in 2014 and he’d never beaten the Swiss in straight sets.

“I had to change something today, for sure. I’d lost to him twice in the last two months,” the Japanese commented. “I was able to play good tennis, using my forehand a little more and playing aggressive, and things started working for me, especially in the second set. I think I played well today.”

Federer holds several tournament records at the ATP Finals: most titles (six), most finals (10), most semifinals (14), most appearances (16) and most match wins at the season-ending event (55).

The World No. 3 wasn’t able to add to those match wins against the No.9-ranked Nishikori, though.

“I felt like we both struggled throughout the first set. You could tell it was a first round,” Federer told reporters after the match. “I actually started to feel better in the second set - we both did, the level went up—but unfortunately I couldn’t keep the lead that I got early, and that was important, I think.

“The 10-minute swing at the end of the first set through 1-all in the second was the key of the match.”

Federer was also asked about Nishikori’s level of play.

“Very good,” he said. “I’m really happy he qualified for this event - not taking me out today, but I’m happy for him because he started playing Challengers early on this year, which was a bold decision. That deserves credit and respect, and I think we all have that for Kei, because he’s a great fighter.”

Federer and Nishikori will play their second round robin matches on Tuesday, with Nishikori playing Kevin Anderson in the afternoon session and Federer battling Dominic Thiem in the night session.

“We haven’t played in a while,” Federer said of Thiem. “But I haven’t thought about that match, to be honest. I wasn’t even thinking who I’m going to play next. I just know I need to do better than today.”

Thiem leads Federer in their head-to-head, 2-1, though they haven’t played since Stuttgart in 2016.

This Week on Tennis Channel:

ATP Finals (Sun - Sun 11.11 - 11.18) - Novak Djokovic, Roger Federer and the world's best collide in the season Finale. Live coverage begins on Tennis Channel Sunday at 7:00am EST.