NEW HAVEN, Conn. (AP)—U.S. Open top seed Caroline Wozniacki got a little help from the entire Yale football team Wednesday as she cruised to a 6-4, 6-1 win over Dominika Cibulkova at the Pilot Pen tournament.

Wozniacki, who won in Montreal on Monday and is this tournament’s two-time defending champion, has a special relationship with the team. She took time last year to visit a Yale practice and talked to the players about mental toughness. They responded this year by appearing en masse, in their jerseys at her opening match.

“They are really nice guys, and that they all came and supported me today was just fun,” she said. “We should make this a tradition.”

Wozniacki got off to a rough start, and was down 4-3 in the first set. In between games, she got some treatment for a stiff back and responded by giving up just two points the rest of the set.

“I was telling myself, ‘I want to play, move your feet, come on let’s go,”’ Wozniacki said. “We don’t want to play three sets of course, I want to win in two.”

It didn’t hurt, she said, to have about 80 good looking guys yelling for her.

“We’ve kind of adopted her as our professional women’s tennis player, and hopefully we’re her American college football team,” Yale coach Tom Williams said.

Wozniacki plays Italian Flavia Pennetta in the quarterfinals. Pennetta advanced with a 6-3, 6-2 win over Olga Govortsova of Bellarus. If Wozniacki wins Thursday, she will clinch the U.S. Open Series championship.

In other matches, Russian Elena Dementieva moved into the quarterfinals with a 7-6 (4), 6-7 (5), 6-4 win over Kateryna Bondarenko of Ukraine.

Dementieva, who is ranked No. 13 in the world, has dropped out of the top 10 for the first time since 2008. She said she spent four weeks in bed after tearing her left calf muscle in June during the French Open, and it has taken her some time to feel comfortable on the U.S. hard courts.

“I expected to play summer matches to get my confidence back, and just to feel the surface” she said. “Unfortunately, I was not able to do so.”

She had plenty of time on the surface Wednesday, playing for just over three hours in a back-and-forth contest that featured 13 service breaks.

She will face Marion Bartoli next. Bartoli beat Anastasia Rodionova 6-3, 6-1 on Wednesday.

Nadia Petrova, playing her second straight match on the grandstand court, beat Bethanie Mattek-Sands in straight sets, 6-3, 6-3. She will face Australian Samantha Stosur in the quarterfinals.

“I’m getting to that stage when I get really confident and feeling ready for the Open,” Petrova said.

Russian Dinara Safina needed two tiebreakers to get by Daniela Hantuchova 7-6 (4), 7-6 (2).

Safina was happy with her serving, which she said has been slow to come back since she ruptured a muscle and suffered a stress fracture in her back in January. She won 73 percent of her first-serve points, and 81 percent in the second set.

“Before it was one of my weapons, but because of my injury I was suffering a little bit,” she said. “Slowly I’m getting my motion back and am starting to use it much more.”

In the men’s draw, top seed Marcos Baghdatis needed three sets to beat Juan Ignacio Chela and earn a quarterfinal berth.

Chela took the first set 6-1, before Baghdatis came back to win the next two 6-3, 6-2.

Baghdatis said he didn’t get much sleep Tuesday night and had a bad morning, getting up earlier than he needed to, because he thought he had an earlier match.

“I was a bit tired, so I started the match like I started my day, basically,” he said. “But then, I found a solution to win. I fought the match. I stopped crying.”

James Blake, who grew up in nearby Fairfield, lost his second-round match in straight sets to Russian Alexandr Dolgopolov 6-4, 6-2.

Blake had won the first game on Tuesday night, before rain forced play to be suspended. When the players got back on the court Wednesday afternoon, Dolgopolov won the first five games, and was never really threatened.

Blake, now 30, has dropped to 111 in the world rankings, but said he still feels he has some good tennis left in him.

“I’ve gotten almost everything in my life through working as hard as I can and putting my head down and hoping for the best, and that’s what I’ve got to do now,” he said. “It’s tougher and tougher as the results aren’t coming.”