NEW YORK, Aug. 30 (Xinhua) -- 23-time Grand Slam champion Serena Williams sailed through to the round of 16 of the US Open for the 18th time in her career after a straight-set victory over rising Karolina Muchova of the Czech Republic on Friday.
Williams, who won the US Open six times, eased past Muchova 6-3, 6-2 after 74 minutes' play.
"Had to go out there on business," Williams said. "I think I tried to do that with all three matches thus far. I knew what my opponent could do. I don't know how I would grade my performance. Just gotta keep playing and believing."
Williams will face No. 22 seed Petra Martic of Croatia in the fourth round.
Martic, who is having a breakthrough season after winning her first WTA singles title in Istanbul and reaching her first Grand Slam quarterfinal at Roland Garros, dismissed No. 12 seed and 2018 US Open semifinalist Anastasija Sevastova of Latvia in straight sets.
Elsewhere, reigning French Open champion Ashleigh Barty, the Aussie second seed, and Czech third seed Karolina Pliskova, chasing her first Slam title, also advanced.
Pliskova, the 2016 US Open runner-up, outlasted Tunisia's Ons Jabeur 6-1, 4-6, 6-4 while Barty dispatched Greek 30th seed Maria Sakkari 7-5, 6-3.
Pliskova next plays British 16th seed Johanna Konta while Barty meets Chinese 18th seed Wang Qiang.
Also advancing was Ukrainian fifth seed Elina Svitolina, who next faces US 10th seed Madison Keys of the United States, a 6-3, 7-5 winner over compatriot Sofia Kenin.
Chinese No. 1 Wang reached the round of 16 after beating Fiona Ferro 7-6(1), 6-3.
"I have nothing to lose. Just try to challenge my opponent," Wang said of the clash against Barty.
