Petrova won two-thirds of the points in her 6-2, 6-1 quarterfinal win over Kirsten Flipkens. Petrova saved all three break-point situations she faced and converted five of the seven changes she had against Flipkens.
Klara Zakopalova advanced Friday with a 7-5, 6-3 victory over Dinara Safina. Zakopalova piled up six service breaks and was helped by Safina's five double faults.
Eighth-seeded Agnes Szavay defeated defending champion Kimiko Date Krumm 6-2, 6-7 (3-7), 6-3 in a match that took 2 hours, 43 minutes. Three third-set service breaks sealed the win for Szavay.
Alisa Kleybanova, the No. 5 seed, topped Ekaterina Makarova 6-1, 6-2, dropping her serve just once.
UPI
