Murray didn't get any break points in the two hours 15 minutes match, while Wawrinka had 11 here Thursday, reports Xinhua.
Wawrinka would next meet No.1 seed Novak Djokovic in the semi-final. Djokovic needed four sets to outscore Russian talent Mikhail Youzhny 6-3, 6-2, 3-6, 6-0.
Warwinka, World No.10, hit as many as 45 winners throughout the match, exactly three times of Murray's 15.
"I thought he played great," said Murray about his opponent.
"That was the hardest part of the match. 5-4 game in the first set was important game. I had a chance to close it out; he had quite a few chances. I made a few mistakes."
The first set was going fine for both players until Murray's service game after 5-4. The winner of Wimbledon saved as many as six set points, but still lost the game and the set to Wawrinka.
The second set went on in favour of the Swiss, who finished another break in the sixth game to extend the lead to 4-2, and then served out the set 6-3.
Murray could do nothing to battle back. The world number three lost another two games to finish the match 6-2.
It was the first time since 2004 for a US Open defending champion to miss the semi-finals.
"I don't think I was playing poorly," said Murray. "I got to the quarter-finals of a Slam, which isn't easy."
It was the first time in his career that Wawrinka reached the last four at a Grand Slam tournament.
"It's amazing for me to be in the first semifinal in a Grand Slam, especially after beating Andy Murray, defending champion," said Wawrinka. "He just won Wimbledon too. He's a great champion."
Wawrinka beat Murray for the second straight time. The 28-year-old big server defeated Murray 6-1, 6-2 in a round of 16 match at ATP Masters 1000 Monte Carlo earlier this year. However, beating a World No.3 player without offering any break point wasn't easy.
"My level of tennis right now is quite good," said Wawrinka. "I'm really confident with myself, with my game on the court."
Meanwhlie, it was the seventh straight semi-final US Open show for Djokovic, and the Serbian powerhouse had already reached at least semifinal in 14 straight Grand Slam tournaments.
"Level of confidence is right at the top, very close, because I have been playing most of my matches here very aggressive, very dominantly," said Djokovic.
"I have been very satisfied with my performances overall in the whole tournament so far. And even tonight, even though I dropped a set, I feel I was in control."
Wawrinka has a 11-game losing streak against Djokovic.
--IANS (Posted on 06-09-2013)