Six-time US Open champion Serena Williams is off to the round of 16 in the 2019 edition after dismissing Karolina Muchova 6-3, 6-2 on Friday at Arthur Ashe Stadium.
The match was level at 3-3 in the opening stanza before the eighth-seeded Williams went on a dominant run, winning six games on the spin to make it 3-0 in the second set against the 23-year-old Czech.
Muchova then broke Williams to make it 3-2, but the 37-year-old returned the favor a game later. In the end, Muchova made a good account of herself but little could be done to stymie Williams' powerful serve.
Williams finished the match having won five of eight break points and with a 67% win rate on first serves.
She'll next face 22nd-seeded Petra Maric after the Croatian bounced 12th-ranked Latvian Anastasija Sevastova earlier on Friday.