Olga Govortsova's victory over No. 2 seed Sam Stosur was her ninth win over a top-20 opponent since New Haven last year.
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STANFORD, Calif. (AP) -- Olga Govortsova figured a few extra matches the past week led to an extra special win.

Govortsova, ranked 83rd in the world, ended a frustrating streak with a convincing 6-2, 6-4 victory over No. 2 seed Samantha Stosur in the second round at the Bank of the West Classic on Tuesday night.

Govortsova won back-to-back matches for the first time this season. She had lost seven of her previous eight entering the tournament.

"It helped that I had the extra match and I played four matches in World Team Tennis last weekend,'' Govortsova said. "I don't think she has played since Wimbledon.''

The 25-year-old from Belarus, who beat Germany's Julia Goerges in straight sets in the first round on Monday, improved her record to 8-13 on the year.

"I was so happy to win this match,'' Govortsova said. "I knew I had to be aggressive and I kept going for my shot. I was trying to play my game and not worry about her ranking.''

Govortsova earned her ninth win over a top-20 opponent and her first since beating Agnieszka Radwanska via retirement at New Haven last year. This is also the first time she's reached a quarterfinal this season.

"When I lost my serve at 5-2, I got a little nervous,'' Govortsova said. "She had nothing to lose and was going for her shots. When it was 5-4 and at break point, I served pretty well.''

Stosur, ranked 13th, reached the third round at Wimbledon. The Australian was knocked out in the first round for the first time since early May - a span of five tournaments.

"She was playing quite well and I wasn't able to combat what she was able to do,'' Stosur said. "Things were slowly turning around and I had a break to go 5-5. I gave myself a chance to get back into the match but I had to win that last game, obviously.''

Stosur had 10 double faults, including two in a row at one point.

"That didn't set a good tone for the match,'' she said. "It is inexcusable to get that many in one match.''

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