Stanislas Wawrinka bounced back from a slow start to topple fifth seed Tomas Berdych in four sets at the US Open.
The No 9 seed from Switzerland had lost the first set to Berdych but he recovered brilliantly to win 3-6 6-1 7-6 (8-6) 6-2 after two hours and 47 minutes.
Wawrinka broke his Czech rival six times in total and registered 36 winners and 14 aces.
Berdych, on the other hand, was his own worst enemy at times as he made 45 unforced errors.
"It's always tough to play against Tomas," Wawrinka said.
"He always puts you under pressure. I'm just really, really happy. Tonight is a night I will never forget."
Wawrinka will now play defending champion Andy Murray in the quarter-final.
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