Stefanos Tsitsipas said he regretted not playing his usual instinctive game earlier in his 6-3 6-2 5-7 4-6 6-1 semi-final defeat against world number one Novak Djokovic at the French Open on Friday.
The Greek, seeded fifth at Roland Garros, came back from the brink to force the Serbian into a decider, where a recent injury resurfaced and killed the tired Tsitsipas's chances.
The world number six, however, believes he made a "huge mistake" by not being more instinctive early in the match on court Philippe Chatrier.
"I wish I could have figured certain things earlier which, I don't know, I felt like it was a total demolition, the fact that I tried those things in practice and tried to implement them in the match," Tsitsipas, who saved a match point in the third set, told a news conference.
"It was something new. I wish I wouldn't have tried these things and tried to stay to my ordinary and basic way of feeling the ball and also trying to dictate the game.
"I think that was a huge mistake today, that I tried this for two sets in a row, then came back to my old way of doing things."
That more instinctive approach worked much better for the 22-year-old, who started to convert his break points, turning the tide in spectacular fashion and forcing Djokovic to man the barricades until the Greek ran out of steam.
"He gave me a really difficult time on the court. Unfortunately towards the end of the match an injury that I had during my match in Rome came back," said Tsitsipas.
"As you saw, it was a good comeback, and I think I played great tennis after that, except the fifth set, which I believe my body was not ready for," he added.
"Physically I wasn't really there."
Tsitsipas was hoping to become the first Greek to reach a Grand Slam final and while the defeat would have stung it was a marked improvement from his last semi-final appearance in a major when he was thrashed 6-2 6-4 6-0 by Rafael Nadal at the Australian Open last year.
"Well, if I think back at the Australian Open I was still a kid, and now I'm turning more into an adult," said Tsitsipas.
"My thinking has changed. I've matured. I've been through a lot of things. I have grown from the people around me, my relationships, people in general...
"I have, of course, more experience in my pocket than before. I've played matches. I've experienced different things. I know when something is good or not, and I can, I think, dictate that earlier."
(Reporting by Julien Pretot; Editing by Toby Davis)
