Top seed Vera Zvonareva advanced to the quarterfinals of the Mercury Insurance Open, as did all the other seeded players in action on Thursday.

The world No.3 surged from a 2-3 deficit in the first set and won ten straight games to defeat Vera Dushevina 6-3 6-0. Zvonareva considers every opponent a challenge, but her next one is especially so. In the quarterfinals Zvonareva will play Sabine Lisicki, who has won 17 of her last 19 matches – the German played the semifinals of Stanford and Wimbledon, and won the title in Birmingham. Zvonareva leads their head-to-head 2-0. And one more thing when we're talking about Lisicki, if you haven't read it yet, do check out our recent in-depth analysis of the German's game.

Quarterfinal pairs (seedings in brackets): Vera Zvonareva (1) vs. Sabine Lisicki (12), Peng Shuai (4) vs. Ana Ivanovic (5), Daniela Hantuchova (8) vs. Agnieszka Radwanska (3), Sloane Stephens vs. Andrea Petkovic (2). (photo: sr_cranks)

Last week at Stanford Ana Ivanovic played her first match since Wimbledon and her first since partnering with coach Nigel Sears and lost to Ayumi Morita 6-3 7-5. Ivanovic blamed nerves for the early loss and said she was trying to impress her new coach.

At her very next tournament Ivanovic's opening match happened to be against the same opponent and the 23-year-old didn't repeat the disappointment. She came back from 5-0 down in the second set to advance to the third round of the Mercury Insurance Open. It was the first time in Ivanovic's career that she has done so. Let's also mention that Ivanovic's comeback took place after her on-court consultations with Sears. Final score: 6-1 7-6(5).

Alberta Brianti will be Ivanovic's opponent in the third round. Brianti upset tenth-seeded Flavia Pennetta in the first round. (photo: sr_cranks)

Svetlana Kuznetsova choked for the first time in her life and blew four match points in the second set tiebreak (two of those with double faults), but still the Russian managed to defeat fourth seed Agnieszka Radwanska and win the Mercury Insurance Open in San Diego. Final score: 6-4 6-7(7) 6-3.

"My knees were shaking and I couldn't push on my serve and now I know why people double fault on match points," said the unseeded Kuznetsova who wasted leads of 4-0 and 6-3 in the tiebreak.

"She's a great player, a top player," said the world No.10 Radwanska. "Now, she's lost some points and she's behind me [in the rankings]. But in the important moments, she was better."

Both Kuznetsova and Radwanska were playing their first final since Beijing in October, when Kuznetsova beat Radwanska 6-2 6-4. By winning her first title in 10 months, Kuznetsova is projected to rise from No.21 to No.14 in the Sony Ericsson WTA Tour rankings.

The victory at the Mercury Insurance Open came at the perfect time for Kuznetsova, just ahead of the US Open, the Grand Slam she won in 2004. (source: Reuters, photo via Sony Ericsson WTA Tour)

Flavia Pennetta eliminated second seed Samantha Stosur from the Mercury Insurance Open and reached the semifinals with a 6-4 6-3 victory. All the top three seeds are out of the tournament now: Jelena Jankovic, Samantha Stosur and Vera Zvonareva.

The world No. 15 Pennetta has never lost to Stosur in their three career meetings, but it’s her first Top 10 victory since last year’s US Open. Stosur is ranked fifth.

During the quarterfinal of the Mercury Insurance Open, Stosur hit no aces and served five double faults, compared to Pennetta’s eight aces and only one double fault. Also, Pennetta had 19 winners and Stosur 12.

The Italian’s opponent in the semis will be Svetlana Kuznetsova. The Russian ended the hopes of qualifier Coco Vandeweghe, who upset third seed Vera Zvonareva in the second round. Kuznetsova beat Vandeweghe 7-5 6-2. (photo by John Bolan)

World No.10 Agnieszka Radwanska took some time off from tennis at the Mercury Insurance Open in San Diego and practiced golf hits. She easily managed to hit the target – that is if it was photographer’s head.

Radwanska, seeded fourth at the tournament, defeated former world No.1 Dinara Safina in the second round and will play Shahar Peer in the quarterfinals.