Stanislas Wawrinka has progressed to the US Open quarter-finals with a four-set victory over Tomas Berdych.
The ninth-seeded Swiss player got the better of his fifth-seeded opponent 3-6 6-1 7-6(8-6) 6-2 to reach the last eight of the tournament.
Wawrinka struggled in the opening set and went down 6-3 but recovered in the second to storm to a 6-1 triumph, hitting five aces and winning 15 out of 18 first-serve points.
The third set proved to be a tight one that the 28-year-old could only win 8-6 on a tie-breaker, but the world number 10 made an easy work of it in the fourth and deciding set, with Berdych ending the fourth-round contest with 45 unforced errors.
Wawrinka will face either Andy Murray or Denis Istomin for a place in the semi-finals.
