Nishikori survives three-set match to move into quarterfinal

MEMPHIS, Tenn. (AP) Top-seeded Kei Nishikori was pushed to three sets in his opening match of the Memphis Open on Wednesday, beating American qualifier Ryan Harrison 3-6, 6-3, 6-4 to advance to the quarterfinals.

Nishikori, the two-time defending champion from Japan who had a bye in the first round, struggled in the opening set against Harrison, who was playing his fifth match in five days. After steadying his play, he jumped to a 4-0 lead in the second set. In the third, he broke Harrison early and each held their serve through the rest of the match.

Earlier Wednesday, fifth-seeded Ivo Karlovic, the runner-up in 2014, was eliminated by qualifier Austin Krajicek 7-6 (4), 4-6, 6-4.

Also, Sam Querrey defeated wild-card entry and fellow American Jared Donaldson 6-4, 6-1 in a match that took less than an hour.

A late match Wednesday featured John Isner, the tournament's third seed, faced Ivan Dodig of Croatia.