In a fantastic twist, however, the fans didn't realize he was actually there to receive their messages!
In a hidden camera prank, Jimmy Fallon's team set it up so fans would simply send record messages for the actor, not knowing he was right behind the curtain. One by one, men, women and children shared their praise for the film, gave thanks to Boseman for "being a hero we need in a time like this" and called out the importance of seeing a "superhero movie with people that look like me." One man loved the movie so much, he said he'd seen in twice in theaters ... and once "on bootleg!"
Each time Boseman revealed himself, the fans went wild, especially one woman who also attended his alma mater, Howard University.
The actor spoke about his time at Howard during his interview with Fallon, explaining how Denzel Washington was one of the benefactors who paid for him to study abroad at Oxford.
"I didn't know at first, I kept this secret my whole career," he explained. "When I came back, I got a beneficiary letter and it said Denzel Washington paid for you. I was like, 'What?'"
"I never wanted to ever say that until I met him and I was doing that Rolling Stone interview and he asked me about it and I was like, I think I can say it now," he continued. "I made it to the point where he's not going to think I'm trying to say something by saying it. The weird that happened was, I did the interview and just before the movie came out, he came and I met him. It was amazing."
Denzel's reaction when Boseman reminded him of his contribution: "He was like, 'Oh, that's why I'm here, you owe me money! I came to collect!'"
Boseman's appearance on "The Tonight Show" was filled with great moments.
Later in the show, he also sat down with Fallon and Marlon Wayans to play a game of "True Confessions," where the three took turns sharing a random fact about themselves. The challenge: to try and figure out who's actually telling the truth.
During the game, one of them revealed he once made out with Madonna at a party where everyone "drunk on Ciroc," while another confirmed he once went out with a Colombian model and her twin sister.