NEW HAVEN: Russian top seeds Nikolay Davydenko and Svetlana Kuznetsova tumbled out of the quarter-finals of the last US Open tuneup on Thursday.

France's Amelie Mauresmo, seeded eighth, won a 20-point first-set tiebreaker en route to a 7-6 (11/9), 2-6, 6-3 victory over Kuznetsova and reach the women's semi-finals at the Pilot Pen men's and women's hardcourt tournament.

Kuznetsova got off to a quick start, winning the first three games of the match, but Mauresmo rallied to hand the reigning French Open champion the defeat.

"I gave her chances to come back," Kuznetsova said. "She started to play very well."

After Kuznetsova easily won the second set, Mauresmo took a 4-2 lead in the third.

"I was just going for it, trying to be aggressive," Mauresmo said. "Not too much panicking."

She said the start of the US Open, last Grand Slam of the year, on Monday was inspiring.

"Just before the Open, I start to really play better, feel good physically, try to find a few things in my game," she said.

American Sam Querrey beat men's top seed Davydenko 6-3, 3-6, 6-4 to book a Friday semi-final berth against Argentina's Jose Acasuso, a 7-5, 6-4 winner over France's Florent Serra.

The defeat gave Davydenko the weekend off before the start of the US Open, where he will be the eighth seed and face a qualifier in the first round.

"I have no chance because (of his) first serve," said Davydenko, who had a trainer work on his right wrist during the match after it became sore from the force of Querrey's serves.

Russian seventh seed Igor Andreev also advanced, defeating Argentina's Leonardo Mayer 6-4, 6-7 (4/7), 6-3. Andreev earned a shot at second-seeded Spaniard Fernando Verdasco, who made quick work of Austria's Jurgen Melzer 6-3, 6-1.

Mauresmo will face another Russian, Elena Vesnina, who beat Anna Chakvetadze 6-1, 7-5 in an all-Russian affair.

Defending women's champion Caroline Wozniacki, the second seed beat France's Virginie Razzano 6-4, 6-3 to book a semi-final clash with third-seeded Italian Flavia Penetta.

Pennetta beat Slovakian qualifier Magdalena Rybarikova 6-2, 6-2 and said every match was good preparation for the Open.

"I just look to be prepared for the Open," she said. "This is my first important thing for me is to just get there and be prepared for a fight."