WASHINGTON, Aug. 16 (Xinhua) -- Ashleigh Barty reached the Cincinnati Masters semifinal for the first time and moved closer to regaining the No. 1 world ranking Friday by beating Maria Sakkari 5-7, 6-2, 6-0.

With one more win, she can move into the top spot for the U.S. Open, taking it back from Naomi Osaka, who had much bigger concerns after dropping out of her semifinal match because of a knee injury.

After splitting sets with Sofia Kenin, Osaka took a timeout early in the third set to have her left knee examined and wrapped. She played only two more points before retiring, sending Kenin into the semifinals for the second straight week.

Last week in Toronto, Kenin knocked off Barty on her way to the semifinals, allowing Osaka to jump ahead of Barty for No. 1. Now they're in position to swap spots again.

Barty will face Svetlana Kuznetsova, who reached her first semifinal of the season by beating third-seeded Karolina Pliskova 3-6, 7-6 (2), 6-3.

Kuznetsova is playing only her ninth event after missing the start of the season because of a knee injury. Playing on a hot, humid afternoon, she got treatment on her upper right leg after the second set and twice again during the final one.