Youngster Oudin continues hot streak at US Open

American teenager Melanie Oudin continued her giant-killing run at the US Open when she knocked out a third Russian seed in succession Nadia Petrova at Flushing Meadows.

The 17-year-old world number 70 from Marietta, Georgia, had already eliminated fourth seed Elena Dementieva and former champion Maria Sharapova, the No. 29 and she returned to Arthur Ashe Stadium to come from a set down to add 13th seed Petrova to her list of victims and reach the last eight.