SZA Battles Simone Biles In Handstand Challenge, Shows Off Flexibility

Simone Biles is the most decorated gymnast ever, but R&B sensation SZA impressively held her own against the GOAT on the mat -- with the two going head-to-head in a handstand competition!!

The friendly contest went down at Biles' gym in a promotion for the 2024 Summer Olympics ... with the Grammy winner meeting the American athlete for the first time, which she called a dream come true.

The "Snooze" artist -- a former gymnast herself -- opened up on her own experiences in the sport ... saying once she knew she wasn't going to be able to compete at the national level, it was time to try her hand at music.

The two stretched as they chopped it up a bit more before the handstand showdown ... with SZA showing off her wild flexibility as she did the splits and answered Biles' questions.

Then, it was time for the main event ... and the two got in formation to see who could stand on their hands the longest.

SZA playfully tried to throw Biles off by getting in her territory ... and while some would consider that cheating, Simone took it in stride.

"She's coming over here?! Haha, she's gonna knock me over," Biles laughed.

Eventually, the tactic worked ... 'cause Biles gave up -- crowning SZA the winner of the handstand-off.

"That was sooooo good," Biles said after taking the L.

Of course, it's not every day you hear about someone beating Biles in gymnastics -- she's got seven Olympic medals ... including four golds. She has also won 23 gold World Championships.