<p>The Dane, who is still searching for an elusive Grand Slam title to support her top ranking, yesterday saw off the tiring 2004 champion Kuznetsova 6-7 (6/8), 7-5, 6-1 and will now tackle Germany's Andrea Petkovic for a place in the semi-finals.<br /><br />In the other quarter-final in the top half of the draw, three-time winner Serena Williams will clash with Russia's Anastasia Pavlyuchenkova.<br /><br />It was a huge struggle for the 21-year-old Wozniacki on a night of fluctuating fortunes on Arthur Ashe Stadium in a gruelling 3hr 2min encounter which finished 2330 local time (0330GMT).<br /><br />She surrendered a 5/2 lead in the first set tiebreak and then slipped 1-4 down in the second set before 15th-seeded Kuznetsova's game fell to pieces.<br /><br />Wozniacki evened the contest on a third set point in the second set and then clinched breaks in the first and fifth games of the decider.<br /><br />Kuznetsova, who was undone by 78 unforced errors, saved four match points in the seventh game but Wozniacki took victory with a smart backhand volley. <br /><br />"I thought about the match we played against each other here in 2009. I was a set and down in the second in that one and still won," said Wozniacki.<br /><br />"I knew I could come back so I just stepped into the lines and went for my shots, tried to make fewer errors. I am in good shape. I can play for five hours if I have to. I just wanted to keep the rallies going."<br /><br />Williams reached the last eight with a 6-3, 6-4 breeze past former world number one Ana Ivanovic and will now face Russian 17th seed Pavlyuchenkova, the youngest player left in the draw.<br /><br />Williams, seeded a lowly 28 after a year spent battling injury and serious illness, has yet to drop a set at Flushing Meadows this year and Ivanovic never looked likely to break that streak.<br /><br />"I feel so blessed to be back. A couple of months ago I never expected to be here," said Williams, 29, who came into the US Open with titles in Stanford and Toronto, her first wins after spending 11 months on the sidelines.<br /><br />Williams said she was looking forward to building on her career tournament victories of 39, which are second only to sister Venus (43) and Kim Clijsters (41) amongst active players.<br /><br />But she was worried over where she will put any more trophies. <br /><br />"I don't have any more space. I have a new house in L.A. I created a karaoke room, so I can't put trophies in there," said Williams.<br /><br />"The other area, the gentleman's lounge, is kinda packed with vintage things I got at a flea market, which is really cool. In Florida, forget it. Venus and I, there's just no more space.<br /><br />"I would love to keep winning them. But we're like, 'Oh, what are we going to do with this one?'"<br /><br />Pavlyuchenkova battled back to defeat seventh-seeded Italian Francesca Schiavone 5-7, 6-3, 6-4 to reach her first US Open quarter-final in a mistake-plagued clash.<br /><br />Pavlyuchenkova triumphed in a match-up of the youngest and oldest players -- 20 and 31 -- left in the women's event.<br /><br />But the tie, which opened the programme on Labor Day, a national holiday in the US, was not for the purists with 21 double faults, 16 breaks of serve and a combined 95 unforced errors.<br /><br />Petkovic defeated unseeded Spaniard Carla Suarez Navarro 6-1, 6-4 to reach her first US Open quarter-final having made the last eight at the Australian Open and at Roland Garros this year.<br /><br />The first two quarter-finals take place today with Vera Zvonareva, the second seeded Russian and runner-up last year, facing Australian Samantha Stosur, the ninth seed.<br />Italian 26th seed Flavia Pennetta tackles unseeded German Angelique Kerber.</p>
<p>The Dane, who is still searching for an elusive Grand Slam title to support her top ranking, yesterday saw off the tiring 2004 champion Kuznetsova 6-7 (6/8), 7-5, 6-1 and will now tackle Germany's Andrea Petkovic for a place in the semi-finals.<br /><br />In the other quarter-final in the top half of the draw, three-time winner Serena Williams will clash with Russia's Anastasia Pavlyuchenkova.<br /><br />It was a huge struggle for the 21-year-old Wozniacki on a night of fluctuating fortunes on Arthur Ashe Stadium in a gruelling 3hr 2min encounter which finished 2330 local time (0330GMT).<br /><br />She surrendered a 5/2 lead in the first set tiebreak and then slipped 1-4 down in the second set before 15th-seeded Kuznetsova's game fell to pieces.<br /><br />Wozniacki evened the contest on a third set point in the second set and then clinched breaks in the first and fifth games of the decider.<br /><br />Kuznetsova, who was undone by 78 unforced errors, saved four match points in the seventh game but Wozniacki took victory with a smart backhand volley. <br /><br />"I thought about the match we played against each other here in 2009. I was a set and down in the second in that one and still won," said Wozniacki.<br /><br />"I knew I could come back so I just stepped into the lines and went for my shots, tried to make fewer errors. I am in good shape. I can play for five hours if I have to. I just wanted to keep the rallies going."<br /><br />Williams reached the last eight with a 6-3, 6-4 breeze past former world number one Ana Ivanovic and will now face Russian 17th seed Pavlyuchenkova, the youngest player left in the draw.<br /><br />Williams, seeded a lowly 28 after a year spent battling injury and serious illness, has yet to drop a set at Flushing Meadows this year and Ivanovic never looked likely to break that streak.<br /><br />"I feel so blessed to be back. A couple of months ago I never expected to be here," said Williams, 29, who came into the US Open with titles in Stanford and Toronto, her first wins after spending 11 months on the sidelines.<br /><br />Williams said she was looking forward to building on her career tournament victories of 39, which are second only to sister Venus (43) and Kim Clijsters (41) amongst active players.<br /><br />But she was worried over where she will put any more trophies. <br /><br />"I don't have any more space. I have a new house in L.A. I created a karaoke room, so I can't put trophies in there," said Williams.<br /><br />"The other area, the gentleman's lounge, is kinda packed with vintage things I got at a flea market, which is really cool. In Florida, forget it. Venus and I, there's just no more space.<br /><br />"I would love to keep winning them. But we're like, 'Oh, what are we going to do with this one?'"<br /><br />Pavlyuchenkova battled back to defeat seventh-seeded Italian Francesca Schiavone 5-7, 6-3, 6-4 to reach her first US Open quarter-final in a mistake-plagued clash.<br /><br />Pavlyuchenkova triumphed in a match-up of the youngest and oldest players -- 20 and 31 -- left in the women's event.<br /><br />But the tie, which opened the programme on Labor Day, a national holiday in the US, was not for the purists with 21 double faults, 16 breaks of serve and a combined 95 unforced errors.<br /><br />Petkovic defeated unseeded Spaniard Carla Suarez Navarro 6-1, 6-4 to reach her first US Open quarter-final having made the last eight at the Australian Open and at Roland Garros this year.<br /><br />The first two quarter-finals take place today with Vera Zvonareva, the second seeded Russian and runner-up last year, facing Australian Samantha Stosur, the ninth seed.<br />Italian 26th seed Flavia Pennetta tackles unseeded German Angelique Kerber.</p>