Richard Gasquet held serve for 13 straight games to cruise past Tomas Berdych at the US Open after being broken twice to drop the first set.
The French 12th seed looked in trouble when he dropped serve twice in succession to lose the opening set but Gasquet hit back to knock off Berdych 2-6 6-3 6-4 6-1 and claim victory in two hours, 27 minutes at Flushing Meadows.
Gasquet won just 25 per cent of points on his second serve in the first set, as Berdych broke him via deuce in the sixth and eighth games.
But Berdych would have just one more break-point opportunity over the next two sets, plus three in the last, as Gasquet won 70, 71 and 63 per cent of second-serve points for the rest of the contest.
The win took Gasquet to just his third quarter-final at a major since 2007, with the 29-year-old set to face world number two Roger Federer in the next round in New York.
Having failed to convert three break points in the first set, Gasquet pounced at his first opportunity in the second set, breaking the Czech sixth seed to lead 3-2 and then claimed another break in the ninth game to level the match.
The sole break of the third set went to Gasquet in the decisive 10th game, while in the fourth Berdych dropped serve in two straight games to capitulate and suffer his first loss to the Frenchman in four meetings.