Flavia Pennetta caused the biggest upset of the US Open so far with a gutsy 6-3 3-6 6-4 victory over third seed Maria Sharapova on Arthur Ashe Stadium.
The 2006 champion, who had been the second favourite for the title, paid for 12 double faults and 60 unforced errors as Pennetta progressed to a fourth-round meeting with Peng Shuai.
The Italian has been ranked as high as 10th and won their last meeting on hard courts in Los Angeles two years ago, so it was by no means a straightforward match for Sharapova.
Second seed Vera Zvonareva survived another battle at the US Open to reach the fourth round at Flushing Meadows.
The Russian was taken to three sets by Kateryna Bondarenko on Wednesday and, although it was straight sets against Anabel Medina Garrigues, she certainly did not have the contest all her own way. Zvonareva, who lost to Kim Clijsters in the final 12 months ago, edged a tight first set and then let a break lead slip away in the second before hitting back to win 6-4 7-5 in exactly two hours.
Meanwhile former mens champion Juan Martin Del Potro eased into the third round with a 6-2 6-1 7-5 victory over Diego Junqueira.
n Sheffield’s Jonny Marray and partner Jamie Delgado are through into the last 16 of the mens double after an epic three set victory over 12th seeds Marcelo Melo and Bruno Soares. The duo edged a tight contest 6-3 6-7 7-6. It equals Marray’s best performance in grand slam doubles. He reached the third round of Wimbledon with Richard Bloomfield two years ago.