Rafael Nadal once again had no trouble at the US Open, while No. 22 seed Philipp Kohlschreiber upset top American John Isner.
Nadal, the second seed, posted his third straight-set victory, beating Ivan Dodig 6-4, 6-3, 6-3.
Nadal has faced only five break points, saving all of them, through three matches. But he doesn't think that's because he's serving particularly well.
"I am winning because I am playing well from the baseline and I am making the right decisions in the right moments," Nadal said.
He'll next face Kohlschreiber, who beat John Isner, at this stage for the second straight year. Isner's 6-4, 3-6, 7-5, 7-6 (5) loss means the host country has only one player left in the men's draw. Tim Smyczek, ranked 109th, plays his third-round match against 43rd-ranked Marcel Granollers on Sunday.
In Saturday's late match, five-time Open champion Roger Federer barely broke a sweat, ousting Adrian Mannarino 6-3, 6-0, 6-2.
Other men's action included fourth-seeded David Ferrer, who needed nearly three hours to down 172nd-ranked qualifier Mikhail Kukushkin 6-4, 6-3, 4-6, 6-4. His next opponent is No. 18-seeded Janko Tipsarevic, who also took four sets to knock off 20-year-old American Jack Sock 3-6, 7-6 (1), 6-1, 6-2.
Eighth-seeded Richard Gasquet and No. 10 Milos Raonic set up another fourth-round matchup with victories.