FLUSHING MEADOWS, N.Y. - The women's top seed at the U.S. Open is moving on...barely.
Caroline Wozniacki fought back from a big deficit and rallied to down No. 15 seed Svetlana Kuznetsova of Russia, 6-7 (6-8), 7-5, 6-1 to make it to the quarterfinals.
The match, which lasted just over three hours, was almost a carbon copy from two years ago when the Danish superstar bounced back for a three-set win in the round-of-16, capturing the final two sets in tiebreakers.
Wozniacki was behind 4-1 in the second set of this Labor Day encounter as the match went deep into the night at Arthur Ashe Stadium.
"I thought about the match we played two years ago. I was down 4-1 in the second set as well," Wozniacki said. "I just stepped into the lines a little bit and went for my shots a bit more and made a few."
Wozniacki, the runner-up in 2009, won four straight games during the second set and capitalized thanks to numerous errors from her opponent. Kuznetsova missed an overhead slam during the four-game run, and when her forehand went long, Wozniacki forced the decisive third set.
She was dominant in that final set and fortunate as well to win the match, thanks mostly to 78 unforced errors from Kuznetsova, the 2004 U.S. Open champion and runner-up in 2007.
Kuznetova fought off a few match points before finally succumbing, as Wozniacki set up a quarterfinal match against 10th-seeded German Andrea Petkovic. She ousted Spain's Carla Suarez Navarro, 6-1, 6-4.
Three-time champion and former world No. 1 Serena Williams secured a berth in the quarterfinals on Monday. The 28th-seeded Williams handled 16th-seeded Serb Ana Ivanovic 6-3, 6-4.
Williams jumped out a a quick 3-0 lead in the first set before her fellow former No. 1 Ivanovic fought back to pull even at 3-all. The Serb then had a break-point chance to grab a 4-3 edge in the stanza, but the American stalwart saved it on her way to winning the last three games of the set.
The 29-year-old Williams then cruised in the second amid windy conditions on Day 8 to reach her ninth career U.S. Open quarterfinal (5-3). The 75-minute exercise came to an end when Ivanovic misfired long on one final forehand return, or her 29th unforced error.
"I thought she played really well," Williams said of Ivanovic. "I think we could have both played a little bit better 'cause of the conditions. But I think we were just both trying to do our best."
"I'm still here in the tournament, so that's pretty good," Williams added. "You know, I just came in here, you know, just trying to do my best."
Ivanovic is now 0-4 in fourth-round Grand Slam matches since capturing the 2008 French Open title.
"My serve broke down little more than hers did," Ivanovic said. "I still created lots of opportunities and I felt I was stepping up a lot, and I just felt that was the biggest difference today."
Williams is now riding a 16-match overall winning streak, all on hardcourts, including titles in Stanford and Toronto. She's 20-2 this season since returning to action in June following an 11-month injury/health-induced layoff.
The superstar owns 13 career Grand Slam titles, including three here in Flushing Meadows, where she was also a runner-up to her older sister Venus in 2001. Serena first tilted in New York as a 17-year-old back in 1999.
Serena will face 20-year-old Russian Anastasia Pavlyuchenkova in the round of eight.
Former French Open champ Francesca Schiavone was a fourth-round upset victim Monday.
The 17th-seeded Pavlyuchenkova upended the seventh-seeded Schiavone 5-7, 6-3, 6-4 at Arthur Ashe Stadium.
Pavlyuchenkova prevailed in 2 hours, 41 minutes on her third match point by swatting a big forehand winner. The sloppy match featured 16 service breaks and 21 double faults, including 11 by the victor.
"I tried not to let her play her game, because she's very smart and she makes me run a lot," Pavlyuchenkova said after toppling Schiavone.
The Russian slugger will now appear in her first-ever U.S. Open quarterfinal.
The 31-year-old Schiavone outlasted Pavlyuchenkova in a French Open quarterfinal back in June. The gritty Italian was this year's French Open runner-up and last year's surprise titlist at Roland Garros.
Pavlyuchenkova was a titlist in Mexico earlier this season.