Top seed Karolina Pliskova advances at Rogers Cup

TORONTO (AP) Karolina Pliskova advanced to the quarterfinals at the Rogers Cup on Thursday when Japanese qualifier Naomi Osaka was forced to retire because of an injury.

The world's top-ranked player moved on with a 6-2, 6-7 (4), 1-0 victory when Osaka had to retire because of an abdominal injury.

It wasn't immediately clear when Osaka suffered the injury. She was in form during the tiebreaker, firing a service winner to convert her second set point under the warm sun at Aviva Centre.