serena-williams

NEW YORK — Serena Williams used a seven-game run midway through the match to grab control and moved into the U.S. Open’s fourth round for the 18th consecutive appearance with a 6-3, 6-2 victory over Karolina Muchova.

Williams had a bit of shakiness with her serve, double-faulting seven times.

Otherwise, she played well, and went from trailing 3-2 at the outset to grabbing the opening set and a 3-0 lead in the second.

Williams is seeking a seventh title at Flushing Meadows and the 24th Grand Slam singles trophy of her career.

On Sunday, she will face 22nd-seeded Petra Martic of Croatia for a quarterfinal berth.

Second-seeded Ash Barty advanced to the round of 16 with a 7-5, 6-3 victory over Maria Sakkari.

Barty, the reigning French Open champ who faced tough tests in her first two rounds, employed a steady baseline game and took advantage of 39 unforced errors from the 29th-ranked Sakkari.

This is the second year in a row Barty has advanced to the final 16. She next faces the winner of the match later Friday between 18th-seeded Qiang Wang and Fiona Ferro.