Simone Biles is the most decorated gymnast ever, but R&B sensation SZAimpressively 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 .