American Coco Vandeweghe stunned third seed Vera Zvonareva in the second round of the Mercury Insurance Open in San Diego, even though the Russian world No.9 dominated the first set and lead by a break early in the second and third sets. Final score: 2-6 7-5 6-4.

The 18-year-old Vandeweghe, ranked 205th in the world, has recorded only her third victory on the Sony Ericsson WTA Tour and it’s already a Top 10 one. Her second main draw win on the Tour came in the first round of the San Diego tournament, against Argentina’s Gisela Dulko.

In the quarterfinals of the $700,000 Mercury Insurance Open Vandeweghe will play another Russian, two-time Grand Slam champion Svetlana Kuznetsova, who toughed it out against Sara Errani 6-1 6-7(5) 7-5 in the second round. (photos by John Bolan)

Top seed Jelena Jankovic lost in straight sets in the second round of the Mercury Insurance Open to Alisa Kleybanova, despite leading 4-0 in the first set. Jankovic even had three set points at 5-3, but Kleybanova won eight straight games to take the score to 7-5 4-0 and eventually win the match 7-5 6-2.

The second-ranked Jankovic said she was afraid to run a lot because it was just her first match since injuring her left ankle in Portoroz two weeks ago. The world No.28 Kleybanova defeated Jankovic two times in 2009 and now leads their head-to-head record 3-2.

The 21-year-old Russian, who won her first WTA title in Kuala Lumpur in February, has reached only her third quarterfinal of the season. (photo: John Bolan)

Dinara Safina ended her six match losing streak in the first round of the Mercury Insurance Open in San Diego but lost in the following round already, in straight sets to fourth seed Agnieszka Radwanska 6-1 6-3. This is Radwanska’s first victory over former world No.1 Safina and their head-to-head record is 2-1 now.

Radwanska’s opponent in the quarterfinals will be Shahar Peer who advanced with a 7-5 6-4 victory over Kazakhstan's Yaroslava Shvedova. (photo by John Bolan)

Former world No.1 Dinara Safina defeated Alona Bondarenko 6-1 7-6(2) in the first round of the Mercury Insurance Open on Monday and snapped a six-match losing streak. Safina, whose season was hampered by a back injury, has slumped to No.35 in the Sony Ericsson WTA Tour rankings and hadn’t won a match since Stuttgart in April.

In the match against Bondarenko Safina decided to take an aggressive approach and it paid off. Here’s what the 24-year-old Russian said:

I needed the win. Last week I lost a tiebreaker and in practice I lost one because I was playing defensive. Tonight I said I'm not going to play defensive and be aggressive and whatever happens, happens.

Very good news is that Safina claims her back is alright now:

I think my back is fine now. Every morning when I wake up and it feels good I say thanks.

Safina’s next opponent will be either fourth-seed Agnieszka Radwanska or Chanelle Scheepers, who reached the fourth round of the 2010 French Open. (source: Reuters, photo by our reader John Bolan)