TORONTO, Canada (AFP) - Japan's Naomi Osaka will return to world number one next week after Czech third seed Karolina Pliskova's loss on Friday (Aug 9) to Canada's Bianca Andreescu in the WTA Toronto quarter-finals.

The Canadian ousted Pliskova 6-0, 2-6, 6-4 after one hour and 49 minutes to doom the Czech's bid to regain the top spot for the first time since 2017.

Australia's top-ranked Ashleigh Barty lost Tuesday to ensure she would be dethroned in next week's rankings. Pliskova would have had a chance to overtake her and Osaka had she reached the Toronto final.

Instead, the home-nation heroine advanced to a Saturday matchup against American Sofia Kenin, who defeated Ukraine sixth seed Elina Svitolina 7-6 (7/2), 6-4.

Osaka faces 23-time Grand Slam singles champion Serena Williams in a later quarter-final that will be their first meeting since last year's US Open final.

Williams argued with the umpire late in the match and Osaka was awarded a game as a penalty. She won the contest for her first Grand Slam title but the controversy surrounding the match left her moment of triumph bittersweet.