Japan's Kei Nishikori shouts after winning a point during his ATP World Tour Finals singles final tennis match against Switzerland's Roger Federer at the O2 Arena in London, Sunday Nov. 11, 2018. Image Credit: AP

London: Seventh seed Kei Nishikori defeated six-time former champion Roger Federer 7-6 (4), 6-3 in their Nitto ATP Finals opener at The O2 Arena here late on Sunday.

Nishikori, who is a two-time semi-finalist at the season-finale had not beaten Federer since March 2014 in Miami. But on Sunday, the Japanese took just 88 minutes to wrap up their intense encounter and put himself in with an early chance of coming through to the semi-finals as one of two qualifiers from the Lleyton Hewitt Group.

Sunday’s win also marked Nishikori’s 43rd match win of the season, that includes three runner-up finishes - at the Rolex Monte-Carlo Masters (where he lost to Rafael Nadal), the Rakuten Japan Open Tennis Championships 2018 (lost to Daniil Medvedev) and the Erste Bank Open 500 in Vienna (lost to Kevin Anderson).

Federer, who has now competed at the year-end championships 16 times, last lifted the trophy in 2011. “I felt we both struggled throughout the first set. You could tell it was sort of a first round. I had my chances maybe a bit more than he did. Then I started to feel better in the second set. I think we both did and the level went up. Unfortunately I couldn’t keep the lead that I got early and that was important at the end. That was the key of the match,” Federer said.

Federer will next play sixth-seeded Austrian Dominic Thiem on Tuesday in the round-robin group. Thiem lost to first-time qualifier and fourth seed Kevin Anderson of South Africa during the earlier afternoon session.

Results
(Singles) Kei Nishikori bt Roger Federer 7-6 (4), 6-3; Kevin Anderson bt Dominic Thiem 6-3, 7-6 (10).
(Doubles) Juan Sebastian Cabal/Robert Farah bt Nikola Mektic/Alexander Peya 6-3, 6-4; Jamie Murray/Bruno Soares bt Raven Klaasen/Michael Venus 7-6 (5), 4-6, 10-5.