India's Sania Mirza [Images] set up a quarterfinal showdown with top seed and defending Maria Sharapova [Images] as she added another high-profile scalp at the WTA Tier I Acura Classic on Thursday.

- Acura Classic: Images from Day 4

Sania defeated eighth-seeded Dinara Safina of Russia [Images] 6-1, 6-2 in the third round in San Diego.

Sharapova had earlier overcome France's [Images] Tatiana Golovin [Images] 6-0, 6-3.

But the Indian could not keep the winning form in doubles and she, and Israeli partner Shahar Peer, went down 6-3, 3-6, 10-12 to Su-Wei Hsieh of the Chinese Taipei and Russia's Alla Kudryavtseva in the second round.

Sania, who has beaten higher-ranked players like Golovin, Peer and Patty Schnyder during the on-going hard court season, had lost to Sharapova 6-2, 6-1 in the fourth round of the 2005 US Open, the only time the two players met.

The unseeded Indian, who was playing Safina for the first time, outpaced her on the baseline and struck powerful strokes to take a 5-0 lead in the first set.

Safina, younger sister of the mercurial Marat Safin [Images], threw her racquet in frustration after sending a forehand wide to drop serve for the third time in the set. She managed to get a break in the sixth game when Sania double faulted on break point, but that was the only game the Russian managed to win in the opening set.

In the final game with Safina serving, Sania earned a break point after the world number 14 double faulted but squandered the opportunity by sailing a forehand beyond the baseline.

However, the 20-year-old Hyderabadi got a second chance with an inside out forehand down the line. She closed out the set with a service return winner.

Safina tried to claw back in the match and broke Sania at love to open the second set. However, the Indian broke back and went on to take a 4-1 lead.

Two games later, Safina served to stay in the match trailing 2-5 but Sania broke her at love to seal the match after an hour and four minutes.

Russia's Maria Kirilenko stunned second seed Jelena Jankovic 6-2, 3-6, 7-5 in the third round while ninth seed Elena Dementieva of Russia turned the tables on fifth seed Marion Bartoli of France 6-4 7-5.

Third seed Anna Chakvetadze [Images] overcame Japan's [Images] Ai Sugiyama 6-4 6-4, and number four Nadia Petrova took down Katarina Srebotnik of Slovenia 6-3 7-6.

In securing her biggest win of the year, the 42nd-ranked Kirilenko attacked the Serb from the opening ball, crushing her backhand, returning her serves and charging the net at every opportunity.

Her new coach, Eric Van Harpen, had promised her a Labrador retriever if she won the match.

"I was thinking, 'Match point, and the dog is mine,'" she said.

Kirilenko said the win was the biggest of her career and hopes it will move her closer to the Russian elite in the top 20.

"With these kind of players, if you play passive it won't work," she said.

"The last two days I tried to play more aggressive and it's helped. I ran well, I changed up the speed and came to the net, so I'm very happy."

In her first tournament since Wimbledon, Jankovic looked flat and admitted the match was hard work.

"I was struggling the whole match. I had a cold. The chances were there, but I didn't do the right thing," she said.

Kirilenko will play Dementieva, who avenged Wimbledon finalist Bartoli for beating her at the 2007 French Open and Eastborune.

"I tried to mix it up more because she likes the pace," said Dementieva. "I wanted to get revenge."

Swiss Patty Schnyder upended compatriot Martina Hingis [Images] 6-1 6-7 6-3 and will face Petrova in the final eight.

Wimbledon champion Venus Williams continued her strong play, defeating sixth seed Daniela Hantuchova [Images] 6-0 6-3 to set up a match with Chakvetadze, whom she beat three weeks ago in Fed Cup.

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