STANFORD, California — Third-seeded Dominika Cibulkova battled past an aggressive Stefanie Voegele on Thursday to set up a quarterfinal clash with Urszula Radwanska at the WTA Bank of the West Classic. Slovakia's Cibulkova let 5-2 leads slip in each set, but emerged with a 7-5, 7-6 (7/5) victory over the Swiss player. “I expected a really tough match, because she's playing really well right now,” Cibulkova said of Voegele, who fired 10 aces in the match. “I played her a long time ago. I remember she plays close to the lines. I knew it would be a tough match. It could have been an easier match for me though — I was 5-2 up first set and 5-2 up second set — but in the end I always made it, and even though it could have been easier, I'm still happy with the win,” she said. Seventh-seeded Radwanska of Poland edged Slovakian Daniela Hantuchova 7-6 (7/3), 7-6 (7/3). Hantuchova led 4-1 in the first set and was twice up a break in the second but failed to hold on. Radwanska trailed 0-3 in the second-set tiebreaker, but won the last seven points to seal the victory. Fourth-seeded American Jamie Hampton reached the last eight with a hard-fought 7-5, 6-7 (5/7), 6-3 victory over US wild card Nicole Gibbs. Hampton next faces Russian qualifier Vera Dushevina, who beat American Madison Keys 7-6 (7/0), 6-2, on Friday. The two remaining quarters will see top-seeded Agnieszka Radwanska, Urszula's sister, face sixth-seeded American Varvara Lepchenko, and Olga Govortsova of Belarus take on fifth-seeded Sorana Cirstea of Romania. Fognini, Seppi in semifinals Seeded Italian players Andreas Seppi and Fabio Fognini reached the semifinals of the Croatia Open Friday. The second-seeded Seppi advanced after Horacio Zeballos retired while trailing 6-5 in the first set. The Argentine had two set points at 5-4. Fognini, seeded No. 3, defeated Martin Klizan of Slovakia 6-4, 6-2 for his 12th consecutive singles victory and his third semifinal at Umag. Fognini won four consecutive games after trailing 3-1 in the first set. Another four-game run in the second set at 1-1 set up the victory. Scheepers out of Baku Cup Israel's Shahar Peer defeated third-seeded South African Chanelle Scheepers 2-6, 7-5, 6-3 on Thursday to advance to the quarterfinals of the Baku Cup. Peer will face Slovenia's Tadeja Majeric in the last eight on Friday. Majeric prevailed 7-6 (5), 6-3 over Tereza Martincova of the Czech Republic, securing victory with three second-set breaks. Ukraine's Elina Svitolina beat Nastassja Burnett of Italy 6-0, 7-6 (3) to line up a quarterfinal against second-seeded Donna Vekic of Croatia. In other games Thursday, Magda Linette of Poland rallied to beat Czech player Kristyna Pliskova 3-6, 6-1, 6-2 and Galina Voskoboeva of Kazakhstan defeated Ukraine's Kateryna Kozlova 4-6, 6-3, 6-1. — Agencies