Aryna Sabalenka said she mentally slipped into a "deep, dark hole" while throwing away a dominant position to lose to Diana Shnaider in the French Open quarter-finals on Wednesday.
The world number one led by a set and 4-1 with a double-break, before becoming increasingly frustrated, spraying 57 unforced errors around Court Philippe Chatrier in a 3-6, 7-5, 6-0 defeat.
"I guess mentally I got into a very deep, deep, dark hole over there, and I just couldn't get back mentally on track," Sabalenka told reporters.
The Belarusian has won all four of her Grand Slam titles on hard courts, but has suffered some demoralising losses at Roland Garros and Wimbledon.
The defeat against Shnaider was reminiscent of her agonising final loss to Coco Gauff in Paris last year.
"I really feel great on clay. I feel great on grass," she said.
"I think just maybe I'm focusing too much that I never won a Slam on each, you know, and maybe it's kind of like making me overthink stuff, makes me overemotional at some moment.
"This is something that I actually have to kind of step back and kind of try to find a solution, because I just am so tired of me losing some matches not in the best way just because I was overemotional."
Sabalenka was the only Grand Slam champion left in the men's or women's singles draws heading into the match.
She wasted a golden opportunity for a first French Open title, with Shnaider picking up the pieces to book a semi-final against Polish qualifier Maja Chwalinska.
"Marta is in great shape. Mirra is playing great tennis... Maja - she's also playing really great tennis," added Sabalenka.
"I mean, maybe this match shows I had the least... chance (out of the remaining players)."
Blustery conditions took their toll on both players, although Shnaider improved as the match went on as Sabalenka increasingly struggled.
The Russian 25th seed made just four unforced errors in the deciding set, compared to Sabalenka's 17.
"I don't know why would they keep the roof open when it's crazy windy," bemoaned Sabalenka.
"But how can I complain if almost for the whole match everything was working okay for me, but then it just slipped away.
"I feel like it (the wind) was getting crazy maybe just because mentally I wasn't really okay...
"I don't know why would they keep it open? Even though I was winning, it was very dirty tennis. I don't know how people could actually just sit there and watch me play.
"Then at some point she stepped in, and she played unbelievable in those conditions."
jc/mw
