Carlos Alcaraz kept the nerves at bay when facing match point against Albert Ramos-Vinolas by forgetting that he was playing at the French Open.

The sixth seed saved match point in the fourth set and rallied from 0-3 in the fifth set to complete a 6-1 6-7 (7-9) 5-7 7-6 (7-2) 6-4 success on Court Simonne-Mathieu.

Teenager Alcaraz enjoyed an emphatic start against his fellow Spaniard, but the experienced Ramos-Vinolas showed admirable poise to take the second and third sets in Paris on Wednesday.

Ramos-Vinolas' ability to fight off break points – coupled with Alcaraz's lack of ruthlessness – gave him the upper hand, and he came within one point of knocking out the Madrid Open champion.

But he crumbled on his own serve at 5-4 in the fourth, and from there Alcaraz's greater mobility and relentlessness when chasing seemingly lost causes had the 19-year-old looking the favourite.

Eventually he came out on top after the longest match of his fledgling career at four hours and 34 minutes, setting up a third-round clash with Sebastian Korda.

"You always have nerves in the match, but I think today I wasn't nervous," said Alcaraz.

"Just maybe at the end of the fourth when I had the match point [to save]. I maybe thought I was one point away from losing, but just try not to think that I'm in the French Open.

"I'm trying to enjoy the moment. I think that in the fourth set, and in the fifth, I smile with my team.

"I enjoy the battles. I want to play big battles and tough battles against the best players in the world."

Alcaraz was won four titles this year, including success at two ATP 1000 events, and feels at home playing on the show courts.

"I'm still young, but I would say pretty experienced player now," said Alcaraz.

"I feel comfortable playing in big stadiums, big matches, playing in grand slams. Physically. I'm strong. Mentally, I'm strong as well.

"I think I'm ready to play these kinds of matches in these situations, these tournaments. I'm ready."