Naomi Osaka says her French Open exit was "probably the best thing that could have happened" and that she was suffering headaches from the "stress" of being the top seed.
Her bid for a third Grand Slam in a row ended with a 6-4 6-2 third-round defeat by unseeded Czech Katerina Siniakova.
The US Open and Australian Open champion was playing in her first Grand Slam as world number one.
"I feel like there has been a weight on me," the Japanese 21-year-old said.
"In this tournament I have had a feeling that was different to the other Grand Slam tournaments.
"Usually, I find it very freeing and fun but this time I was kind of tense the entire time.
"I think I was overthinking this calendar Slam."
Osaka made 38 unforced errors as she lost in one hour and 17 minutes to world number 42 Siniakova on a stunned Court Suzanne Lenglen.
"It is incredible, it is something I can't believe, I'm so happy," Siniakova said after reaching the last 16 of a Grand Slam singles for the first time.
The 23-year-old right-hander is ranked as the world's leading women's doubles player and won that competition at the French Open last year alongside fellow Czech Barbora Krejcikova.
"Roland Garros brings out my best and I hope it will continue," she added.
Siniakova will play 14th seed Madison Keys for a place in the quarter-finals after the American came through a testing encounter with 20-year-old Russian Anna Blinkova 6-3 6-7 (5-7) 6-4.