Beijing, China – Italian veteran Flavia Pennetta toppled world No. 1 and defending champion Caroline Wozniacki in Friday's quarterfinal action at the $4.5 million China Open tennis event.
The unseeded Pennetta came from behind to stun the top-seeded Danish star in 3-6, 6-0, 7-6 (7-2) fashion on the hardcourts at the National Tennis Center. The sloppy match featured 14 service breaks, including eight by the surprise winner.
Wozniacki has now lost three of her last seven matches.
The six-time 2011 WTA titlist Wozniacki defeated Russian Vera Zvonareva in last year's Beijing finale.
Eleventh-seeded Pole Agnieszka Radwanska avoided an upset and remained red hot with a 6-3, 3-2 victory over former world No. 1 Ana Ivanovic, who retired in the second set on Day 7 due to a back injury. Radwanska is fresh off her title last week in Tokyo, where she upset Zvonareva in the final at the Pan Pacific Open.
Radwanska will meet Pennetta in Saturday's semifinals.
Romanian qualifier Monica Niculescu became a surprise semifinalist by overcoming 2005 Beijing titlist Maria Kirilenko of Russia, 3-6, 6-3, 6-4.
The 2011 China Open champ will pocket $775,500.
