"I know you're a strong dude. I've seen Magic Mike 12 times. But I bet I can take you in an arm wrestle," Fallon, 39, boasted to the 22 Jump Street star. Tatum said: "Is that so?"
"I'm serious," Fallon replied. "I've been working out a lot lately—Curves gym."
The two men then made their way to a wooden table to compete, rambling off several things they would do if they won. "After I win, I'm gonna go get my hair did and hit up Applebee's because you know tonight is girls night out," Tatum, 34, joked.
Fallon, meanwhile, had traveling on the brain. "After I win, I'm going to stuff myself in a duffel bag so only my head is sticking out. Then ride around an airport carousel and yell, 'A little help!'"
Tatum, trying to one-up him, teased: "After I win, I'm going to start texting you so you see that little typing bubble come up. Then I'll wait about five years and then write, 'K.'"
Watch the hilarious video above, and see who won!