By Martyn Herman
LONDON (Reuters) - Japan's Kei Nishikori dispatched error-strewn Swiss Stan Wawrinka 6-2 6-3 in a disappointingly one-sided clash at the ATP World Tour Finals on Monday.
What had promised to be a standout tussle between the world's third and fifth-ranked players failed to deliver as Nishikori won the group opener in little more than an hour in front of a subdued O2 Arena crowd.
From the opening game when Wawrinka had to save two break points the 31-year-old struggled and Nishikori duly got the first break in the fifth game with a punishing forehand.
Nishikori was ruthlessly efficient and quickly polished off the first set aided by a second break when U.S. Open champion Wawrinka double-faulted to end a woeful service game.
Wawrinka tried to pump himself up at the start of the second set, delivering a couple of signature backhands, but he was still struggling to locate his A-game.
The crowd, far from a sell-out, wanted more for their money but a miscued Wawrinka forehand into the net gave Nishikori a break point in the fifth game which he converted when Wawrinka elected to leave a return that floated in.
Nishikori, who could still finish the year at a career-high third in the ATP rankings, claimed some revenge for this year's U.S. Open semi-final loss when he broke again to end the contest after Wawrinka wafted a lazy backhand over the baseline.
Home favorite and new world number one Andy Murray takes on Marin Cilic later on Monday in the same John McEnroe group.
(Editing by Ed Osmond)