Marion Bartoli recovered from a set down to stun Petra Kvitova and progress to the last eight at the US Open.
The Frenchwoman was swamped early on and lost the first set to the 2011 Wimbledon champion 6-1.
Kvitova could not have anticipated the fight in the 11th seed, who rattled off 12 of the next 13 games to take the final two sets in convincing fashion.
The fifth seed was stunned and failed to make at least the quarter-finals of a Grand Slam for the first time this year.
Bartoli now progresses to face either Maria Sharapova or Nadia Petrova in the next round.
