SAN DIEGO: California teenager Coco Vandeweghe rallied to upset Wimbledon runner-up Vera Zvonareva 2-6, 7-5, 6-4 Thursday to reach the quarter-finals of the WTA San Diego Open.

Qualifier Vandeweghe, ranked 205th in the world, shook off her poor start to topple the ninth-ranked Russian, who is seeded third in the hard court event.

Vandeweghe won her second straight main draw match after dropping 13 of her previous 15 career WTA matches.

Zvonareva appeared to be headed toward an easy victory when she broke Vandeweghe`s serve three times in the opening set.
By the time Vandeweghe held serve, she trailed 5-2.

But the 18-year-old from the San Diego area seemed to gain confidence from the encouragement of the crowd.

She and Zvonareva exchanged early breaks in the second set before Vandeweghe gained a decisive break and served out to level the match.
Vandeweghe served for the match at 5-3 in the third, but Zvonareva converted her third break point to trim the lead to 5-4.

But Vandeweghe put away the match in the next game with a blistering forehand winner on her first match point.

In the quarter-finals she`ll face Russian Svetlana Kuznetsova, who defeated Italian Sara Errani 6-1, 6-7 (5/7), 7-5.

Fifth-seeded Italian Flavia Pennetta defeated Maria Kirilenko 6-4, 7-6 (7/5), notching two early breaks to pocket the opening set before falling behind 5-2 in the second.

She responded by winning four straight games, but was broken at love when serving for the match at 6-5.

Kirilenko saved one match point at 6-4 in the tiebreaker before Pennetta was able to close it out.

"After the first set, I just relaxed a little bit," Pennetta said. "She was making some mistakes at the end of the first set so I was thinking she was going to do the same.

"But she started to play better and more aggressive. I was a little too far from the (base)line and I was running too much."

Pennetta will face second-seeded Australian Samantha Stosur in the next round.

"I have to rest now and be ready for running so much," Pennetta said. "When she hits the ball it`s really powerful. My return is going to be really important."

In another second-round match, Slovakia`s Daniela Hantuchova defeated China`s Zheng Jie 6-2, 6-1.

BDST: 1332 HRS, August 6, 2010