Andy Murray's US Open title defence ended tamely as Swiss ninth seed Stanislas Wawrinka outplayed him in the quarter-finals at Flushing Meadows.
The Briton, seeded third, failed to earn a single break point in a 6-4 6-3 6-2 defeat on Arthur Ashe Stadium.
Murray has struggled to find his best form since winning Wimbledon two months ago and his frustration was clear when he was given a code violation for racquet abuse.
"It was a tough day for me," Murray told BBC Radio 5 live.
"He played exceptional tennis and served very, very well. He hit a lot of lines on big points, went for his shots and they all went in today. He played too well."
In a match many had predicted would go to five sets, it took only two hours and 15 minutes for Wawrinka's brilliant attacking game to prevail on a hot and blustery afternoon in New York.
The 28-year-old moves on to his first Grand Slam semi-final, where he will face world number one Novak Djokovic who beat 21st seed Mikhail Youzhny 6-3 6-2 3-6 6-0 in the night session.