Tennis-Madrid Open women's singles quarter-final results

Madrid Open women's singles quarter-final results on Friday (prefix denotes seeding, * new result): * Lucie Hradecka (Czech Republic) beat 5-Samantha Stosur
(Australia) 7-6(8) 7-6(6) 4-Agnieszka Radwanska (Poland) beat Varvara Lepchenko (U.S.) 6-4 6-4 9-Serena Williams (U.S.) beat 2-Maria Sharapova (Russia) 6-1 6-3 1-Victoria Azarenka (Belarus) beat 8-Li Na (China) 3-6 6-3 6-3