World number two Naomi Osaka suffered a surprise third-round defeat to Swiss wildcard Jil Teichmann at the Cincinnati Masters.
The Japanese star, 23, lost 3-6 6-3 6-3 to the world number 76.
“I have high expectations of myself but there was nothing more I could do to win this match,” Osaka said.
Elsewhere, top seeds Daniil Medvedev and Ashleigh Barty are among the big names through to the quarter-finals in Cincinnati.
Russian world number two Medvedev beat Bulgaria’s Grigor Dimitrov 6-3 6-3 in the men’s draw.
He extends his winning streak