New York: Maria Sharapova reached the US Open quarterfinals for the first time since her 2006 championship run with a 6-1, 4-6, 6-4 victory over Russian compatriot Nadia Petrova on Sunday.

And defending champion Samantha Stosur of Australia set up a last-eight showdown with top seed Victoria Azarenka as both captured fourth-round triumphs on the Flushing Meadows hardcourts at the year's last Grand Slam tournament.

Third seed Sharapova, who completed a career Grand Slam by capturing the French Open title last June, rallied after twice dropping four games in a row and having to sit through a 73-minute rain delay.

"I'm so happy to be in the quarters," Sharapova said. "It has been so many years and it's a great stage to be at."

Seventh seed Stosur squandered eight match points but finally subdued stubborn British teen prodigy Laura Robson 6-4, 6-4 in 98 minutes.

She advanced to a quarter-final against an opponent she has never defeated, World No. 1 Azarenka of Belarus, who ousted Georgia's Anna Tatishvili 6-2, 6-2, to reach her first US Open quarter-final.

"As defending champion she's going to be really motivated. I'm motivated as well," Azarenka said. "It's my first quarter-final at the US Open and I'm really looking forward to it."

Sharapova will next face French 11th seed Marion Bartoli, who beat Czech fifth seed Petra Kvitova, the 2011 Wimbledon winner, 1-6, 6-2, 6-0, to book her first trip to the US Open quarter-finals at her 11th attempt.

"I'm speechless and that doesn't happen very often," Bartoli said. "It has been my dream to play well in New York. It's one of the best matches of my season. I was moving so well. I was seeing so well on the court."

Sharapova leads Bartoli 4-0 in their career rivalry, having never dropped a set to her French rival with her most recent triumph in a 2010 Cincinnati quarter-final.

But it almost fell apart against Petrova when she surrendered a break in the last game of the second set and the second game of the third set just before rain arrived.

That sent the players back to the locker room, where Sharapova spoke to coach Thomas Hogstedt.

"He told me to get my act together. That was quite important," Sharapova said. "The beginning of the third was quite sloppy. He just told me to fight. And I talked to my dad and he said got to keep fighting. So I did."

Sharapova broke back in the first game after play resumed and broke again in the seventh game, pumping her fists with every point and again after taking the match when Petrova netted a forehand after two hours and 14 minutes.

Petrova, who fell to 1-9 all-time against Sharapova, failed in her bid to match her best US Open runs from 2004 and 2005 when she reached the semi-finals.

Stosur, Australia's first women's Grand Slam champion since 1980, eliminated Robson, the first British woman in the last 16 at the US Open since 1991.

"I'm playing really well," Stosur said. "I'm glad to get another match. I'm happy to be into the quarters again."

Stosur has lost all six career meetings with top seed Azarenka, never taking a set off the reigning Australian Open champion. Azarenka's most recent victory over Stosur came in last February's Doha final.

"There's a few things I've learned over those matches that I can put into play and have a much better match and hopefully a very good one," Stosur said.

"You have to be 100 percent prepared as soon as you serve, have your game plan and stick to it."

Robson, an 18-year-old from England ranked 89th, had sent three-time US Open champion Kim Clijsters into retirement and 2011 French Open winner Li Na out of the event in the previous two rounds.

But the youngest woman in the world's top 100 finally faltered under the pressure of the reigning queen of the Flushing Meadows hardcourts.

"Definitely disappointed. I felt like I didn't play as well as I did in my last three matches," she said. "I just hit too many unforced errors."

Azarenka, who won her first Grand Slam title at this year's Australian Open, has now cracked the last eight in every Grand Slam event.

It will be Azarenka's fifth quarter-final in the past seven Slams. She can ensure she stays atop the rankings next week by reaching the final, but first she must maintain her mastery of Stosur.

"She's very dangerous," Azarenka said. "What she did here last year was absolutely amazing. It's definitely going to be a very difficult match.

Bartoli denied left-hander Kvitova her first trip to the last eight after she had been the only player to reach the quarter-finals in this year's three prior Slams.

(Agencies)

Latest News from Sports News Desk