NEW YORK -- Victoria Azarenka kept chiding herself: "Don't be a chicken."
So when she faced a break point against the defending U.S. Open champion late in the final set, Azarenka didn't care that she hadn't hit an ace all day. She knocked a booming serve down the middle, the ball barely clipping the line out of Sam Stosur's reach.
Pushed to the limit, the world's top-ranked player hung tough in Tuesday's quarterfinals for a victory in a third-set tiebreaker.
"When you're facing a break point, you don't feel like you're going to hope for a mistake," Azarenka said. "You have to make it happen. You have to change the momentum. You have to create something that will surprise her. (She) has the momentum going; she's feeling confident. She has a chance. I had to come up and be strong.
"So I was like, 'OK. Let's do it. If I miss it, I miss it.' "
Azarenka eked out a 6-1, 4-6, 7-6 (5) win in 2 hours, 23 minutes -- not including an early 76-minute rain delay. She had never lost even a set to the Australian in six previous meetings, but Stosur rallied time and again after a lopsided first set.
"I enjoy the fight," Azarenka said. "I enjoy that struggle, that pain that we go through, that incredible moment that you feel relieved after you gave it all in every point you had."
Because of rain that halted play on and off through the day, Azarenka was the only woman who got to enjoy a singles victory at the U.S. Open on Tuesday. The other women's quarterfinal on the schedule was suspended in progress because of rain, and four-time major champion Maria Sharapova will be trailing 2007 Wimbledon runner-up Marion Bartoli 4-0 when they resume Wednesday.
Sharapova got a bit of a reprieve from the weather during her previous match: She was down 2-0 in the third set against Nadia Petrova when a rain delay of 75 minutes came: After the break, Sharapova took five of the next six games. She'll get at least 15 hours to contemplate her deficit against Bartoli, who lost all eight sets they had played before Tuesday.
They were allowed to head to their hotels before 6 p.m. because the tournament wanted to free up Arthur Ashe Stadium for the night session and the main event: 2003 U.S. Open champion Andy Roddick's bid to postpone retirement yet again by beating 2009 champ Juan Martin del Potro in the fourth round. The rain stopped around 7:30 p.m. and the Roddick-del Potro match began about an hour later than scheduled. Play, however, was halted right after Roddick went ahead 1-0 in a first-set tiebreaker. A little more than a half-hour later, the tournament called off play for the day.
The seventh-seeded Stosur came back from down a break twice in the third set. She had a chance to go up a break at 5-5 when Azarenka hit that lone ace.
Then in the tiebreaker, Stosur recovered from trailing 4-0.
"There was momentum here, momentum there," Stosur said. "We were hitting winners and running all over the court."
At 5-all in the tiebreaker, Stosur's forehand nicked the net cord and landed short, and Azarenka put the point away with a drop shot.
"I was lucky that the ball caught the net. I was just trying to stay in the moment," Azarenka said. "I didn't really feel like what was the score. I had to do something to surprise, because at this moment you have to come up with something different, not the usual what you do. Because one or two shots will just decide everything."
On match point, Azarenka's final forehand touched down on the baseline, forcing Stosur into a crouch and a wild backhand.
Azarenka improved to 11-0 in three-set matches this year. She had never before made it past the fourth round at the U.S. Open.
The Australian Open champ from Belarus kept Stosur on the run in the first set, breaking her three times. But in the second, Stosur started channeling the aggressive play that allowed her to upset Serena Williams in the final here last year, pounding big forehands for winners.
"I think I'm capable of beating her one day," Stosur said. "Just would have liked it to have been today."
Stosur conceded it had been a "rough" year since she broke through for that first Grand Slam title. She lost in the first round at home at the Australian Open and in her second match at Wimbledon.
But she had the look of a major champion again back here at Flushing Meadows and finally found some answers Tuesday against an opponent who had bedeviled her.
"To really turn it around in one of the biggest tournaments of the year, that's what we come out here and play for," Stosur said. "I think that proves to me that I am capable of doing it. To have another showing here at the Open like this, it for sure gives me confidence to think that maybe one day I can do it again."
The tiebreaker got back on serve after Azarenka double-faulted. She used an expletive later to describe that second serve.
"It was just terrible, terrible," she said. "Wrong movement. I was not focused enough on my execution, what I had to do."
But, Azarenka added, "these kind of mistakes are easier to deal with because they're just silly."
Stosur tied it up with an overhead, but Azarenka was unfazed.
"She really pushed me to dig deep," Azarenka said. "We fought really hard. I felt like there wasn't something (where) somebody was missing. It was always somebody had to grab the opportunity to provoke mistakes. ... The quality of tennis was really high, and it was tense because it could go either way."
The win assured Errani of moving up to No. 1 in the WTA doubles rankings, with Vinci at No. 2. Errani and Vinci won the French Open doubles title in June.
Errani and Vinci are scheduled to face each other in the singles quarterfinals Wednesday. This will be their sixth match as foes in singles, and Errani leads 3-2.
"There will be tension, the way there always is in any match, the way there was in the first round, the second round, the third round. It's a quarterfinal," Errani said. "Maybe, in theory, we'll actually be a little calmer, because we know one of us moves on in the tournament. One of us will win, one will lose."
Errani and Vinci aren't the only women's doubles team that wound up getting sent to opposite sides of the net in singles at Flushing Meadows this year. Vania King of the U.S. and Yaroslava Shvedova of Kazakhstan, the 2010 Wimbledon and U.S. Open doubles champions, met in the first round; Shvedova won in straight sets, and both nearly cried afterward.
"Our friendship is more valuable than a tennis match, even if it is a quarterfinal or semifinal at a Slam," Errani said.
Then, using a mock-serious voice, she added: "But tomorrow, I hope to not lose a friend."
Information from The Associated Press was used in this report.