Daniil Medvedev has never been comfortable in the Roland Garros spotlight and the Russian crashed 6-2 1-6 6-1 1-6 6-4 to Australian wildcard Adam Walton for his seventh opening-round defeat in 10 appearances at the Grand Slam.
"I don't want to find excuses," he said.
"I know why I don't really play my best at Roland Garros, but if I say it, it's excuses. So I'll keep it to myself.
"Maybe I should consider playing a tournament before (it), which I usually don't do before Grand Slams, but when it doesn't work, why not? That's the only thing I'll consider next year."
Walton said hailing from Queensland and being comfortable in furnace-like conditions helped him prevail.
"I grew up in the heat. I've always preferred when the court gives my shots extra, which is what the heat does," he added.
"I seem to be able to last. I'm not saying I last better than him, but I last better than probably the field in the heat.
"Just given the way I play, that's one aspect that is huge for me, because I'm not the most talented player out there."
Walton was joined in the next round by compatriot Alex de Minaur, who advanced after rising Belgian Alexander Blockx was forced to withdraw with a right ankle sprain, while Alexandre Muller retired injured trailing Stefanos Tsitsipas 6-2 3-0.
Briton Cameron Norrie pulled out injured from a major for the first time as a rib issue meant he was unable to continue after going down 7-6(7) 2-0.
American Learner Tien dished out the bagels during his 6-0 2-6 6-0 6-2 win over Cristian Garin, while compatriots Zachary Svajda, Emma Navarro, Iva Jovic, Claire Liu, Ann Li all went through with little trouble.
A day after French favourite Gael Monfils went out of his home Grand Slam for the final time, Parisian fans were given a glimpse of the future as teenager Moise Kouame downed 2014 U.S. Open champion Marin Cilic 7-6(4) 6-2 6-1.
Victory meant the 17-year-old wildcard became the youngest man to win a Grand Slam main draw match in 17 years.
"It's a lot of emotion, it's exceptional," Kouame said.
"Coming into this tournament, I didn't know what to expect.
"The team and I worked hard to be as ready as possible."
American fifth seed Jessica Pegula became the biggest casualty in the women's draw when she was beaten 1-6 6-3 6-3 by Australian Kimberly Birrell.
Reigning Paris champion Coco Gauff recovered from a sluggish start to outclass Taylor Townsend 6-4 6-0 with several Americans also progressing despite a heat wave in the French capital making conditions challenging for players and fans.
Jannik Sinner began his quest for a maiden French Open title to complete the career Grand Slam with a 6-1 6-3 6-4 win against Frenchman Clement Tabur in the evening session on Court Philippe Chatrier.
The Italian's only mistake in a near-flawless performance was to give a bit of hope to Tabur in the third set, but the 24-year-old was always a cut above as he claimed his 30th victory in a row.
Dressed in a black-and-red mesh outfit and wearing a diamond necklace, Sabalenka dismissed Spain's Jessica Bouzas Maneiro 6-4 6-2 before brushing off concerns about the added flourish by saying she was completely at ease.
"I like to challenge myself," the Belarusian told reporters.
"But at the same time, the dress is super light ... I don't feel the dress on me. I was thinking it's going to be super hot wearing black, but it doesn't feel like black colour on me, I feel really comfortable.
"And the diamonds, I don't really feel the heaviness of it, but I can imagine how it looks from the outside ... for me, it's important to look good. If I feel good looks-wise, I perform better and I feel great."
While Sabalenka set the tone, former world number one Osaka added a touch of Parisian flair as she walked onto Court Suzanne Lenglen in a sequined blouse and a black mesh floor-length train before unveiling a layered yellow-brown and gold match dress.
The tennis was equally sparkling as the 16th seed overcame tricky German Laura Siegemund 6-3 7-6(3) before hinting at the inspiration behind her match outfit.
"I feel like ... you know the Eiffel Tower at night when it's sparkly? I think I look like that a bit," Osaka said.