Gymnastics legend Dominique Dawes is keepin' it real ... telling TMZ Sports Simone Bileswould've SMOKED her in competition -- even during her prime!!
"Biles is unreal," the 3-time Olympian says. "She is so talented, and I am so grateful that I’m retired because I would have just not even had a chance going up against this young girl."
It's high praise, considering Dawes is a gymnast icon -- remember, she was part of the famous Magnificent Seven Olympic team in 1996, and she also won silver and bronze medals at World Championships in the '90s.