Australian Sam Stosur beat Russian Nadia Petrova 7-6, 6-7, 7-5 to reach the last 16 of the US Open in a three hour, 16 minute battle on Friday in the tournament’s longest women's match of the tie-break era.
Ninth seed Stosur, a quarter-finalist in New York last year, had chances to close out a hard-fought tussle in the second set, but Petrova, the 24th seed, saved two match points and won the tiebreak 7-5 to force a third set.
Then it was Stosur's turn to rally back. Down a break in the third set, the Australian drew level at 4-4 with a service break in the eighth game.
A confident hold at love gave Stosur a 6-5 lead, and she finally finished off Petrova on her fifth match point.
Maria Sharapova was knocked out in a shock third round loss to Flavia Pennetta.
Sharapova was beaten 6-3, 3-6, 6-4 in the biggest upset of the tournament so far before Andy Murray clawed his way back from being two sets down, to defeat Robin Haase of The Netherlands 6-7, 2-6, 6-2, 6-0, 6-4 in the second round and avoid another early exit.
Leander in quarters
India's Leander Paes and Elena Vesnina entered the mixed doubles quarterfinals beating Taipei-Polish combine of Yung-Jan Chan and Mariusz Frystenberg 6-2, 6-7, 10-4 in a tight second round match.
Vesnina then teamed up with Sania Mirza to post a 6-1, 7-6 win over Russian Vitalia Diatchenko and Ukraine's Olga Savchuk in the second round of the women's doubles.
The Indo-Pak duo of Bopanna and Aisam-Ul-Haq Qureshi defeated James Cerretani and Philipp Marx 7-6, 7-6 to enter the third round.