The Brit prevailed, 7-6(8), 7-5, 6-0, against the dangerous Argentine and was striking the ball with renewed confidence after a turbulent start to the year.
Murray believes the victory, secured in just under three hours, arrived at just the right time in the French capital.
A welcome test
“To play him this early on in a slam is obviously not easy,” mused Murray in his post-match press conference.
“But at the same time it can be a very positive thing, because if you play someone that good maybe you’re a little more switched on, perhaps your focus is higher.
“It was a good one for me to get through.
“Each set I began to play better and I made adjustments during the match that helped me which is very positive.”
The pair exchanged breaks during the opening set and it was decided in a tie-break after an hour of action.
Murray prevailed, 10-8, after the South American double-faulted on set point and says after that moment he felt it would be an uphill struggle for his opponent considering the conditions.
Important first set
“The conditions were very slow and heavy so coming from behind in those conditions can be difficult because it feels you have to work very hard for every point,” he added.
“His reaction at the end of the first set, he was pretty disappointed as he had some opportunities, obviously double-faulting in the tie-break on one of the set points."
Del Potro’s forehand was cooking during the opening frame but the world number one was able to tame his biggest weapon during sets two and three.
“It’s a very big shot,” highlighted Murray.
“I played a lot into his forehand today, a lot of guys on the tour with big forehands tend to like their forehands into the backhand corner plus he’s pretty good on the run with it.
“On clay though it’s a little bit more difficult for him because you’re a bit more unstable on your feet which makes you harder to read.”