The Swiss number two defeated the 2012 champion 6-4 6-3 6-2 to reach the last four of a Grand Slam for the first time in his career.
"It was a tough day for me," Murray told BBC Sport.
"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."
Murray went on to defend his own performance, pointing out that reaching the quarters of a Grand Slam is an achievement.
"I was playing well enough to get to the quarters," he added.
"It's not an easy thing to do, there's only eight other guys in the tournament who have been able to do that.
"I've played my best tennis at the Slams the last three years. It wasn't maybe my best day today, but the last three years have been great for me and especially the last year."