Myles Garrett Defeats Girlfriend Chloe Kim In Cute Race

Myles Garrett might be dating Chloe Kim, but he made it clear he's never gonna take it easy on her in competition -- crushing the Olympic gold medalist in a race ... backwards!!

The superstar snowboarder shared the footage on Thursday ... showing the lovebirds lined up for a sprint at a training facility, but the Cleveland Browns defensive end was facing the opposite direction.

To be completely fair to CK, she didn't seem anywhere close to 100% ... and she was wearing street clothes.

Garrett, meanwhile, was decked out in workout gear ... so even though he backpedaled through the race, it was clear he was gonna come out on top.

Kim was playful about the whole thing ... saying, "99% sure I would've won if I wasn't wearing jeans."

TMZ Sports broke the story ... the two made their public debut at an anime awards show in Japan last month -- and sources at the event said they were as adorable toward each other as could be.

Seems like we'll be seeing the Team USA hero in Northeast Ohio this fall ... so perhaps her winning ways will rub off on the Browns??