SAN FRANCISCO: Dominika Cibulkova, who was playing her first match since reaching the quarter-finals of Wimbledon, defeated Urszula Radwanska 7-6 (7/3), 6-3 in her opening match at the WTA Stanford tournament on Thursday. The second seeded Slovak was one of the last among the top seeds to begin play at the California hardcourt tournament. Cibulkova jumped out to a 5-2 lead in the first set but Radwanska roared back to force the tiebreaker before Cibulkova prevailed in just over an hour. The pair traded breaks in the second set before Cibulkova was able to clinch it in the ninth game. “At the right time, I was focused and I didn’t panic though I lost a few games I should have won. My forehand was working and I knew I had to go for that, and I had to play smart today because I knew she was playing really well,” said the world No. 12 Cibulkova. Cibulkova will face Japan’s Misaki Doi in the quarter-finals. She is hoping that a strong performance in Stanford will vault her back into the top 10 in the world rankings. In other matches, 17-year-old Catherine Bellis beat Sachia Vickery 4-6, 6-4, 6-3 in a battle between two players ranked 203rd and 204th in the world. The American teen next faces 36-year-old top seed Venus Williams for a berth in the semi-finals when the two duke it out on Friday night. Bellis is no stranger to upset victories as she first burst onto the scene as a 15-year-old in the 2014 US Open when she stunned Cibulkova in three sets, 6-1, 4-6, 6-4. Six months later she reached the third round of the Miami event where she faced Serena Williams for the first time. Friday’s contest will be her first time playing seven-time Grand Slam winner Venus Williams. Bellis was born five years after Venus played her first career WTA Tour match at this event in 1994.