Ana Ivanovic suffered the earliest defeat for a women's top seed in US Open history as she was stunned by 188th- ranked qualifier Julie Coin 6-3, 4-6, 6-3 on Thursday in the second round.
Roland Garros winner Ivanovic, troubled for months by a sore thumb, became the first top seed at the event to lose before the third round, the dpa reported.
That record was set by Billie Jean King in 1973.
Ivanovic was over-run by the 25-year-old Coin from northern Amiens, France. The Serb seed contributed to her own downfall with eight double faults.
The Open was the first Tour-level event for Coin, winner of four minor titles below the WTA level.
Her nerves played a huge role, with a double fault on her first match point before closing it out with a scream on a third winning chance.