Italian teenager Lorenzo Musetti said his five-set French Open loss to Novak Djokovic gave him the belief that he can compete with the very best despite his upset bid falling short against the 18-time major champion.

The 19-year-old Grand Slam debutant took the first two sets off the world number one Monday before retiring due to injury with Djokovic leading 6-7 (7/9), 6-7 (2/7), 6-1, 6-0, 4-0.

"It was a fantastic experience. I was playing my best tennis, for sure. I have never played like today," said the 76th-ranked Musetti.

The first two sets took 75 and 66 minutes, after which Musetti faded badly. He claimed just 18 more points as Djokovic rallied from two sets down to win for the fifth time in his Grand Slam career.

"Of course I'm a little bit disappointed, but I played against the No. 1 in the world, and I took the first two sets," said Musetti.

"He started to play really good, and then I had some physical problems. I think I have to work there."

It was just the second time Musetti had played five sets, having gone the distance against compatriot Marco Cecchinato in the previous round.

"The match with Cecchinato was like five sets, three hours, and was really tough, was really intense," he said.

"Maybe if I had played like three sets instead of five today would have been different. 

"But, I mean, you cannot compare. I'm happy with this week and with the tennis that I have showed today."

Musetti will now turn his attention to Wimbledon, "his favourite Slam", buoyed by his stirring run to the last 16 at Roland Garros.

"I think I took away a lot of feelings, a lot of emotions, but a lot of experience," he said.

"Now I know how can I play, how far I am from the biggest in the tour, like Nole, so I know that if I play good I can stay at this level."