NEW YORK:Melanie Oudin extended her remarkable run at the US Open to the quarter-finals with another thrilling 1-6, 7-6 (2), 6-3 victory over 13th-seeded Nadia Petrova of Russia.

The 17-year-old Oudin staved off two points that would have put her behind 5-3 in the second set, then rolled through the third, hitting corners with those underrated groundstrokes and taking advantage of 22 unforced errors by her more-seasoned, higher-ranked opponent.

The 70th-ranked player already had wins over No 4 Elena Dementieva and No 29 Maria Sharapova at the Flushing Meadows. Now, she’s knocked off No 13. She has become the youngest American to enter the quarter-finals at America’s Grand Slam since Serena Williams in 1999.

Oudin will play No 9 Caroline Wozniacki of Denmark, who stunned two-time major champion Svetlana Kuznetsova 2-6, 7-6 (5), 7-6 (3).

In other women’s matches, Kateryna Bondarenko of Ukraine and Belgian Yanina Wickmayer won to set up a quarter-final match.

In men’s play, No 1 Roger Federer beat No 14 Tommy Robredo of Spain 7-5, 6-2, 6-2 and will face No 12 Swede Robin Soderling, who advanced when No 8 Nikolay Davydenko of Russia retired with a leg injury at the start of the fourth set.

American John Isner lost to No 10 Fernando Verdasco of Spain 4-6, 6-4, 6-4, 6-4. Verdasco will play fourth-seeded Novak Djokovic of Serbia, 6-1, 6-3, 6-3 winner over 15th-seeded Czech Radek Stepanek.