World number one Caroline Wozniacki has kept her hopes of securing her first Grand Slam title alive with victory over Svetlana Kuznetsova at Flushing Meadows.
The Dane looked to be heading out of the tournament when she trailed by a set and 4-1, but battled back to win 6-7 [6/8] 7-5 6-1 at the Arthur Ashe Stadium.
After the match, the 21-year-old revealed that she is in "good shape" for the remainder of the competition.
"I thought about the match we played against each other here in 2009. I was a set and break down in the second in that one and still won," she said.
"I knew I could come back so I just stepped into the lines, went for my shots, and 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."
Wozniacki will now take on number ten seed Andrea Petkovic in the quarter-final.
