Cincinnati sf

But US Open: Elena Rybakina's quest to dethrone Aryna Sabalenka at the top of the WTA Rankings ended when she was forced to retire from her Cincinnati Open quarterfinal match against Iga Swiatek with a left ankle injury.

Swiatek was leading 4-1 with Rybakina serving at 40-15 when things first appeared to go wrong. Rybakina couldn't finish off a rally at the net, and when Swiatek put a tough passing shot at her feet, the Kazakh missed the follow-up half volley and put her hands to her knees.

She struggled to push off on her first serve on the next point, which lasted just three shots, and after a mid-game medical evaluation, Rybakina elected to end the match moments later, WTA reports.