SAN DIEGO (AFP) — World No. 1 Iga Swiatek, seeking her eighth WTA title of the year, cruised over eighth-ranked Coco Gauff on Friday to reach the San Diego Open semifinals.

In a rematch of this year's French Open women's final, the 21-year-old Polish star rolled over 18-year-old American Gauff 6-0, 6-3 in 65 minutes.

Three-time Grand Slam champion Swiatek advanced to a Saturday semi-final against sixth-ranked Jessica Pegula, who defeated 18th-ranked US compatriot Madison Keys 6-4, 7-5.

"I'm pretty happy that we're going to play against each other because it's a test for me of where my level is because she's really, really solid," Swiatek said of Pegula.

"Our matches are always physical and really tight. Even though sometimes the scores are one way, you can see during the games we always have deuces and any point can matter."

Swiatek is 3-1 all-time against Pegula, having lost their first meeting in 2019 at Washington but won this year at the Miami semifinals and US and French Open quarterfinals.

"She plays super athletic, aggressive, defends really well," Pegula said of Swiatek.

"She does everything at a really high level."

Croatia's 77th-ranked Donna Vekic made the semifinals by ousting fifth-ranked Aryna Sabalenka 6-4, 6-7 (5/7), 6-1.

Vekic will next face 19th-ranked American Danielle Collins, who defeated Spain's fourth-ranked Paula Badosa 7-6 (7/5), 6-4.

Swiatek won her WTA-best 62nd match triumph of the year in her tour-best 12th quarterfinal of the season.

Swiatek, a runner-up last week at Ostrava, seeks her 11th career WTA title and her eighth of the year after crowns at Qatar, Indian Wells, Miami, Stuttgart, Rome and the US and French Opens.

Gauff fell to 0-4 all-time against Swiatek, having lost last year in Rome and this year at Miami and Roland Garros, where Swiatek dispatched her 6-1, 6-3 for the trophy.

Swiatek broke three times to lead 5-0, saved two break points in the final game and held to claim the opening set after 29 minutes. Swiatek broke to open and close the second set for the victory.

Vekic improved to 5-1 all-time over Sabalenka after two hours and 37 minutes to reach her first semifinal of the year.

Collins broke at love to force a first-set tiebreaker, which she won when Badosa sent a backhand wide.

In the second set, Badosa hit a backhand long to hand Collins a break for a 4-3 lead and held twice for the victory, closing it out on a forehand crosscourt winner after two hours.