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Key Biscayne, FL (SportsNetwork.com) - Australian Open runner-up Dominika Cibulkova came from behind to upset third-seeded Agnieszka Radwanska and reach the semifinals at the $5.4 million Sony Open.

The 10th-seeded Cibulkova staved off three match points in the second set and overcame a 2-5 deficit in a tiebreak before outlasting the former Wimbledon runner-up Radwanska, 3-6, 7-6 (7-5), 6-3, on the hardcourts at Crandon Park.

With her big quarterfinal victory on Wednesday, the 24-year-old Cibulkova will enter the Top 10 in the WTA rankings for the first time in her career next week. She headed to Miami at No. 11 in the world.

"This win really means a lot to me," Cibulkova beamed in her on-court interview. "It's always tough to play Aga, but I knew I just had to stay aggressive. If you make some mistakes with Aga you still have to stay aggressive. That's the way I play, and it's the only way to beat her. I had to keep it going."

Radwanska, who was the runner-up in Indian Wells two weeks ago and the Miami champion in 2012, was also upset by Cibulkova in an Aussie Open semi back in January.

Cibulkova's final-four opponent on Thursday will be second-seeded Li Na or 11th-seeded former world No. 1 Caroline Wozniacki. Cibulkova lost to Li in January's Aussie Open finale.

Thursday's other semifinal will pit current world No. 1 Serena Williams against fourth-seeded former top-ranked Russian star Maria Sharapova. The American great topped Sharapova in last year's final to capture a sixth Miami title and hand the Russian her fifth loss in five finals at this lucrative tournament.

Williams is a dominant 15-2 lifetime against Sharapova, including 14 straight wins dating back to 2004. The American is 3-0 versus the Russian in Miami.

The 2014 Sony Open champ will collect $787,000.