The Dane is into her first Grand Slam quarter-final in two years after reproducing some of the form that saw her end 2010 and 2011 as world number one.

Wozniacki made a fast start, racing to a 3-0 lead.

Five-time Grand Slam champion Sharapova levelled to 4-4, but the Russian fifth seed was unable to resist an on-form Wozniacki, who took the opening set 6-4.

Two breaks of serve gave Sharapova a 6-2 second set win to level the match and take it to a decider.

With stifling temperatures on the court of Arthur Ashe Stadium, both players were given a 10-minute break.

And it was 10th seed Wozniacki who moved back into the ascendency when they returned, attacking Sharapova's shots.

With most of the crowd on Wozniacki's side, the 2009 US Open finalist took the decider 6-2 to send the crowd into raptures.

"It means so much to me - it's been a bit up and down for me this year," she said.

"It's a new year and I've gotten older, and hopefully a little wiser.

"I feel good. I feel comfortable when I play out there.

"The crowd was amazing today.

"It's just so much fun to play out there again on the big court."

Also into the quarter-finals is Italian Sara Errani.

The 13th seed beat Croatian Mirjana Lucic-Baroni 6-3, 2-6, 6-0.

Meanwhile, ninth seed Jelena Jankovic of Serbia beat Swiss Belinda Bencic 7-6, 6-3.

A two-hour rain break gave Roger Federer enough time to regroup and reel off the next three sets 6-1 to move into the fourth round ©Getty Images



In the men's singles, Roger Federer was on the ropes after losing his first set to unseeded Spaniard Marcel Granollers 6-4.

A two-hour rain delay at the end of the first set seemed to come at the perfect time for the Swiss number two seed, who is on the hunt for a sixth US Open title.

He reeled off the next three sets, all with the scoreline 6-1, to glide into the fourth round at Flushing Meadows.

He will meet Spanish 17th seed Roberto Bautista Agut, who overcame Frenchman Adrian Mannarino 7-5, 6-2, 6-3.

There was an upset at Louis Armstrong Stadium, as fourth seed David Ferrer crashed out.

The Spaniard was beaten by Gilles Simon of France, the 26th seed, 6-3, 3-6, 6-1, 6-3.

Sixth seed Tomas Berdych of the Czech Republic had a more straightforward passage into the fourth round, beating Russian Teymuraz Gabashvili 6-3, 6-2, 6-4.

In a battle of the Frenchman, Gael Monfils, the 20th seed, beat 12th seed Richard Gasquet in straight sets 6-4, 6-2, 6-2.

Tomorrow will see women's top seed Serena Williams of the United States in fourth round action against Estonia's Kaia Kanepi, and British eighth seed Andy Murray up against Franc's Jo-Wilfried Tsonga.