New York: Stanislas Wawrinka ensured a first for Switzerland at the US Open when he edged out big-serving American Sam Querrey 7-6, 6-7, 7-5, 4-6, 6-4 to reach the quarter-finals for the first time.
Wawrinka wrapped up a gruelling victory in four hours 28 minutes to join five-times champion Roger Federer in the last eight, the first time two Switzerland has ever had two men in the quarter-finals of a grand-slam event.
"He is a great player and to beat him in five sets is crazy for me," Wawrinka said in a courtside interview. "I was trying to fight for every point and keep playing aggressively. I am very happy with this win."
Number 25 seed Wawrinka, who upset fourth seed Andy Murray in the previous round, took to the court with the right thigh that he injured against the Scot heavily wrapped.
But the wrap did not seem to affect his movement at all and he snatched the first-set tie-break 11-9 to move ahead.
Querrey, the last remaining American in the draw, then dropped his serve in the ninth game of the second set but Wawrinka squandered four set points and 20th seed Querrey took his chance, forcing another tie-break and winning it 7-5.
When he broke in the third game of the third set on his way to a 3-1 lead, Querrey looked like he might run away with the match but Wawrinka hit back well and broke in the 12th game to move ahead again.
But Querrey refused to give up and with the rallies getting longer, he snatched the fourth set to level once more.
The deciding set was nip and tuck throughout but Wawrinka finally snatched the vital break, finishing off victory with a nice backhand volley to reach his first grand-slam quarter-final.
Wawrinka will now play Russian 12th seed Mikhail Youzhny for a place in the last four.