American teenager Melanie Oudin beat another Russian player, her fourth in succession, to make the quarter finals of the U.S. Open on Monday. The 17-year-old beat 13th seed Nadia Petrova 1-6 7-6 6-3. She had earlier disposed of Anastasia Pavlyuchenkova, 4th seed Elena Dementieva and 2006 champion Maria Sharapova. Despite losing the first set, Oudin came back to seal victory, finishing with a forehand winner on her third match point. She could now face another Russian, Svetlana Kuznetsova, or Dane Caroline Wozniacki for a place in the semi finals.