Halep is playing in her first event since beating Williams in the Wimbledon final.

In the afternoon, Bianca Andreescu became the first Canadian Rogers Cup semifinalist since 1979, overcoming a groin injury to beat third-seeded Karolina Pliskova, 6-0, 2-6, 6-4. Andreescu will face Sofia Kenin, a 7-6 (2), 6-4 winner over sixth-seeded Elina Svitolina.

Andreescu, 19, of nearby Mississauga, Ontario, is returning from an injury to her right shoulder that had sidelined her since the French Open in May. She won in Indian Wells, Calif., in March for her first WTA Tour title.

“In the third set I told myself, ‘Go big or go home,’” Andreescu said. “Literally go home. My home is like two minutes from here. I just went out there and I never gave up because it’s not over until it’s over.”

Andreescu played her fourth consecutive three-set match. She needed a medical timeout in the second set for treatment of the groin injury.

“It’s not easy, that’s for sure,” Andreescu said. “Right now, I’m just really happy my mind and my body are holding up. My team, too — I’m so sorry, guys, for putting you through all of that.”