Tennis world number one Andy Murray says he's happy with his performance at Roland Garros this year, despite losing out to Stan Wawrinka in the semi-final on Friday evening.

The Swiss progressed after more than four-and-a-half hours of play, emerging victorious on a scoreline of 6-7 (6-8) 6-3 5-7 7-6 (7-3) 6-1.

Murray has struggled for form so far this year, but says his performance at the French Grand Slam signaled a timely improvement ahead of Wimbledon.

"I'm proud of the tournament I had," he said after his defeat. "I was one tie-break away from getting to the final - even when I was really struggling. I have to be proud of that.

"Maybe the lack of matches hurt me a little bit. It was a high intensity match and when you haven't been playing a lot, matches of over four-and-a-half hours can catch up with you a little bit.

"But I turned my form around and ended up having a really good tournament all things considered."

The 30-year-old admitted Wawrinka's durability in the final set was enough to see him book his place in the final against Rafa Nadal.

"He played better in that set. I lost a little bit of speed in my serve which wasn't allowing me to dictate any points on my own serve. 

"He obviously hit some great shots in the fifth set, but I didn't keep the score close enough to keep him under pressure."

Wawrinka now meets the Spaniard, who overcame Dominic Thiem in straight sets.