World No. 1 Iga Swiatek eased past Coco Gauff 6-0, 6-3 on Friday night in the quarterfinal round at the WTA 500 San Diego Open.

Gauff got off to the worst possible start with a double fault on the opening point as Swiatek took control of the match.

“I just kept my focus and I´m happy that I stayed composed tonight,” Swiatek said. “It was one of those matches where I felt in control from the first point.”

Swiatek next faces fourth-seeded Jessica Pegula in the semifinals.

Earlier, Pegula beat unseeded Madison Keys, 6-4, 7-5.

In the other semifinal Donna Vekic beat Aryna Sabalenka 6-4, 6-7 (5), 6-1, to act up a meet with American Danielle Collins, who beat Paula Badosa of Spain 7-6 (5), 6-4.