Caroline Wozniacki upset French Open champion Maria Sharapova in a ground-stroke marathon to reach the U.S. Open quarter-finals, while Gilles Simon registered the first big surprise in the men's draw on Sunday.
France's Simon, the 26th seed, defeated Spanish fourth seed David Ferrer, who became the first top 10 men's seed to be shown the exit when he fell 6-3 3-6 6-1 6-3 in the third round at Flushing Meadows.
But it was the women's fourth-round match-up between Sharapova and Wozniacki that stole the show.
The 10th-seeded Wozniacki, who ruled as world number one for 67 weeks but never won a grand slam crown, showed great grit in battling to a 6-4 2-6 6-2 victory over fifth seed Sharapova in a two-hour 37-minute slugfest in sweltering conditions.
Victory sent the 24-year-old Dane to her first grand slam quarter-final since the 2012 Australian Open. Italy's Sara Errani awaits as her opponent.
Wozniacki used her stellar footwork and notable fitness to stymie Sharapova, who was forced into a slew of 20-stroke rallies that fit the Dane's game plan.
Wozniacki, who is in training to run this autumn's New York City Marathon, won the hard-fought first set by breaking Sharapova in the last game.
Sharapova dominated the second set to level the match at one set apiece when officials gave the players a 10-minute break invoking the heat rule.
It was an emotional triumph for Wozniacki, whose personal life underwent a tumultuous year.
Wozniacki's slide down the rankings coincided with her dating and subsequent engagement to major golf champion Rory McIlroy.
This year, the Northern Irish golfer called off their wedding days after invitations were mailed.
Photos: Reuters, AFP, TNP, USA Today Sports
"It means so much to me," she told the Arthur Ashe Stadium crowd. "It's been a bit up and down year for me.
"To win against a champion like Maria is an unbelievable feeling."
Asked if she would skip any additional training for November's marathon run, Wozniacki said: "I think this afternoon I'm just going to take a nice bath, have a massage and chill. And I think I deserve to have some chocolate or something." - Reuters