NEW HAVEN, Conn. (AP) -- Sergiy Stakhovsky completed two matches on Thursday, but it was top-seed Marcos Baghdatis who looked tired, losing 5-7, 6-1, 7-6 (4) to the Ukrainian in the quarterfinals of the Pilot Pen tennis tournament.
Stakhovsky changed speeds throughout the match and used slices and drop shots to keep Baghdatis running. In the end, it was the ninth seed advancing to Friday's semifinals.
"I had to make a lot of sprints, you know,'' Baghdatis said. "I felt my legs a bit tired after. I couldn't be 100 percent.''
Stakhovsky was a bit tired, too.
He had his first-round match on Tuesday suspended by darkness and finished that Wednesday, beating Peter Luczak 6-3, 7-6 (4). He started his third-round match Wednesday night against Spaniard Tommy Robredo, before that was suspended by rain in a first-set tiebreaker. Stakhovsky won the tiebreaker 7-5 when the match resumed Thursday morning and finished off the sixth seed in the second set, 6-2. He was back on the court against Baghdatis a few hours later.
"I would say I have a nice long streak here in tennis,'' he said. "I don't need a hotel. I could sleep in the lounge.''
Stakhovsky will play Thiemo de Bakker Friday in the semifinals. The Dutchman, whose ranking has moved this year from No. 96 to No. 52, beat Evgeny Korolev of Kazakhstan, 6-4, 6-2.
In the women's draw, three Russians played their way into the semifinals, while top-seeded Caroline Wozniacki advanced without ever taking the court.
Wozniacki's opponent in the quarterfinals, Italy's Flavia Pennetta, withdrew from the tournament with an injury to her right foot.
"I never like to withdraw, but my foot has been bothering me since last week and I knew that I would not be able to finish the match, so I decided to pull out and not risk any further damage,'' she said.
Wozniacki, who played two matches Monday to win in Montreal before playing here Wednesday, said she was happy to get the night off.
"I can relax a little bit,'' she said. "I can come back tomorrow strong and rested.''
The Danish star will play Elena Dementieva in the semis. The fourth-seeded Russian needed almost three hours to beat Marion Bartoli of France 6-3, 3-6, 6-2. It was her second consecutive three-hour match after beating Kateryna Bondarenko on Wednesday 7-6 (4), 6-7 (5), 6-4.
"Sometimes you have to go through such a difficult match, very long three sets, to feel your game, to feel your confidence,'' she said.
In an all-Russian quarterfinal, Maria Kirilenko beat Dinara Safina in straight sets, 6-3, 6-3. Kirilenko said she's not surprised so many Russians are doing so well on the Tour.
"We work a lot,'' she said. "That's why I think we have good results, you know. Because to have a talent, it's not enough. You have to be patient. You have to work a lot. You have to fight. Everything together. So I think that's why we have so many Russians.''
She will play Nadia Petrova on Friday, who also advanced in straight sets, 6-2, 6-1 over Australian Samantha Stosur. Petrova had four aces and won 82 percent of her first-serve points.
"I got a lot of free points with (my serve),'' she said. "I just really tried to stay consistent with the returns. My goal was to have a good power behind the ball and also be consistent with my shots, not to give too many free points.''
The other men's semifinal Friday will have Denis Istomin of Uzbekistan playing Serbian Viktor Troicki.
Troicki beat Radek Stepanek of the Czech Republic 6-2, 6-3. Istomin needed three sets to get by Teymuraz Gabashvili of Russia 6-1, 3-6, 7-6 (8).