The prank was a total surprise to both studio audiences, who seemed surprised and elated to see Kimmel and Fallon appear in one another’s places after in-studio voiceover announced the regular hosts. Fallon actually got a standing ovation from masked audience members, leading him to say, “Please, please, settle down. You’re going to offend the other Jimmy.” Kimmel took the joke further, introducing himself as Fallon and leaping straight into the monologue as if he were the host. Though his full introduction isn’t visible in the clip posted to YouTube, the full episode makes it clear that the host got a warm welcome from surprised fans as well.

The pair followed up their monologues by chatting live with one another, and Kimmel joked that “a big chunk of [Fallon’s] audience almost left when I walked out.” Though audience members anticipating the live show could have genuinely been disappointed by the unexpected switch-up, the April 1 air date should have given them a heads up that something surprising might go down. All in all, this bit works as a pretty great show of camaraderie among late show hosts–a field that’s historically gone through periods of infighting and contention.

To cap off a surreal night, The Red Hot Chili Peppers managed to appear as musical guests on both shows. You can catch the episodes of both “Jimmy Kimmel Live!” and “The Tonight Show Starring Jimmy Fallon” on Hulu.