"Jason Bourne would kick the s--t out of Batman—absolutely!" Damon told E! News. "Batman's gotta take on Superman first. If he could beat him then maybe he could take on Jason Bourne."
So what does Mr. Affleck have to say about them there fightin' words?
"Matt is going around saying this all over the place but not to my face," Affleck told E! News' Maria Menounos while he was promoting Batman v Superman: Dawn of Justice with his co-star Henry Cavill. "But Matt can't even beat me up, never mind Batman. You know what I'm saying? He has a long way to go."
The two lifelong best friends will be seeing each other sooner than later. "They're just finishing the Bourne movie now when we have our premiere over in London," Affleck said. "I'll see Matt and he can take me up on it."
No doubt Affleck was probably in the best shape of his life while shooting Batman v Superman.
Director Zack Snyder had a gym on set. "He was very supportive of the idea of everyone working out, being in shape, being fit," Affleck said.
Unfortunately, Cavill had to deal with Superman's...hair product!
"It stings the eyes," Cavill said. "Like when it's raining, it's coming down and you're covered with your own hair gel all over your face. It burns."
Batman v Superman: Dawn of Justice is in theaters on March 25. Amy Adams reprises her role as Lois Lane. Gal Gadot plays Wonder Woman and Jesse Eisenberg is the creepy villain Lex Luthor. Rounding out the cast are Jeremy Irons, Diane Lane, Laurence Fishburne, Holly Hunter and Scoot McNairy.