The Swiss number two described defeating the 2012 champion as "amazing" and admitted that he was a "tough" opponent.
"Andy Murray's the defending champion, he's a tough opponent. For me to get through in three sets is amazing," he told BBC Sport.
"The first set was not easy. It was really windy today. To get that set gave me confidence for the rest of the match.
"So much was going through my head in the last game. I just try to be focused, to play solidly, aggressively, to take the match and not let him back."