Czech Karolina Pliskova advanced to the Canadian Open quarter-finals Thursday, seeing off Estonia’s Anett Kontaveit 6-3 7-5 in 79 minutes.

In position to reclaim top spot in the world rankings this week, the third seed in Toronto set up a match against Bianca Andreescu after the Canadian beat fifth-seeded Kiki Bertens of the Netherlands 6-1 6-7 (9-7) 6-4.

The 19-year-old Andreescu improved to 5-0 against top-10 opponents this year.

Pliskova finished off Kontaveit in straight sets after needing three against American Alison Riske on Wednesday.

“For sure better than it was maybe yesterday,” Pliskova said.

“So I guess it’s going to get better every day with what I play. And I always was, I am, improving with matches.”

Fourth-seeded Simona Halep of Romania, making her first start since beating Williams for the Wimbledon title, beat Russian veteran Svetlana Kuznetsova 6-2 6-1 and will face the winner of the night match between Czech qualifier Marie Bouzkova and Latvia’s Jalena Ostapenko.

Sofia Kenin’s good tournament continues following a 6-2 6-2 victory over Ukrainian teenager Dayana Yastremska.

Kenin beat top-ranked Ashleigh Barty in the previous round and in the last eight will face sixth-seeded Elina Svitolina of Ukraine, a 6-2 6-4 winner over 11th-seeded Belinda Bencic of Switzerland.

The Australian will be replaced as world No.1 when the new rankings are revealed on Monday by either Pliskova or Naomi Osaka.

In the night session, Serena Williams takes on Russia’s Ekaterina Alexandrova with the winner to play No.2 seed Osaka of Japan or Polish qualifier Iga Swiatek.

Playing her first event since losing the Wimbledon final, Williams opened with a 6-3 6-3 victory over Belgian Elise Mertens. The 37-year-old Williams has won the event three times, all in Toronto.