TIANJIN, China — Karolina Pliskova and Timea Bacsinszky both won Friday at the Tianjin Open, and they will next face each other in the semifinals.

The top-seeded Pliskova, who is still hoping to qualify for a third straight WTA Finals in Singapore, beat Katie Boulter 5-7, 6-0, 6-3 despite being down a break in the third set.

Bacsinszky, who had been sidelined for six months with a right leg injury, upset fourth-seeded Aryna Sabalenka 7-6 (2), 7-6 (5).

Before playing in Tianjin, Bacsinszky hadn't won a tour-level match since the 2017 Wimbledon tournament.

Sabalenka was one of five players to enter the tournament with a chance to qualify for the WTA Finals, but the loss to Bacsinszky ended those chances.

Also, second-seeded Caroline Garcia advanced to the semifinals when sixth-seeded Petra Martic retired with an abdominal injury while trailing 6-2, 1-0.

Garcia will next play fifth-seeded Hsieh Su-Wei, who also won because of a retirement. Third-seeded Elise Mertens cited a right arm injury for stopping the match while trailing 6-2, 4-0.