Sania Mirza [Images] bowed out of the women's singles at the Cincinnati Open after losing to top seed Patty Schnyder of Switzerland [Images] on Friday night.
The ninth seeded Indian ace was beaten 6-7(7), 5-7 in the quarter-finals.
In other quarter-final action, fourth seed Katarina Srebotnik of Slovenia beat sixth seed Marion Bartoli of France [Images] 6-2, 6-1 while Vera Zvonareva of Russia [Images] proved too good for fifth seed Jelena Jankovic of Serbia and Montenegro, winning 6-1, 6-1.
In the last quarter-final, Serena Williams [Images] beat Amy Fraizer 6-2, 6-2.
Sania and her Polish partner Marta Domachowska are in the semifinals of the doubles event, having scored a hard fought 6-4, 5-7, 7-6 victory over the Chinese-Uzbek pair of Meng Yuan and Varvara Lepchenko.