You never thought the punch that would knock Rocky to the ground would be thrown by a 24 year old girl.

That girl was none other than megastar singing sensation Demi Lovato, who sparred with Sylvester Stallone yesterday at the Unbreakable Performance Center in West Hollywood.

“I slipped! I slipped!” Stallone says as he gets up from the mat after giving a terrific mock-boxing-match performance. “I slipped, I swear, it was an accident!”

“Just knocking out Rocky (@officialslystallone),” Lovato wrote on her Instagram, coupled with these awesome video clips. “Easy day at @unbreakableperformance.. #nobigdeal #boxingLEGEND.”

Lovato regularly works out at Unbreakable, a gym which is frequented by celebrities like Dwayne “The Rock” Johnson and pro-athletes, but is also open to the rest of us.

Check out the Instagram videos of Stallone boxing Lovato below – first, expert boxing choreographer Stallone coaches the singer on how to throw a fake punch convincingly on camera, then the pair go at it!

The making of….

A video posted by Sly Stallone (@officialslystallone) on