Jon Stewart may have retired from "The Daily Show" earlier this month, but that doesn't mean he hasn't been keeping himself busy... which, for his lower back, might actually be a bad thing.

Stewart brought it on himself, though! While hosting "WWE SummerSlam" on Sunday night, the beloved comedian interrupted a match (while the referee was knocked out, of course) by taking a metal chair to John Cena's midsection, leaving competitor Seth Rollins free to finish Cena off and win both the WWE World Heavyweight Championship and United States Championship titles. Which, let's face it, was bound to cause some considerable beef between Cena and Stewart.

(It's also pretty funny considering Stewart's ALSO had beef with Seth Rollins -- maybe he was just trying to get on his good side this time around?)

Last night on "Monday Night Raw" in Brooklyn, Stewart reappeared to explain his actions, and the Cenation Leader retaliated the only way he knows how: by throwing Stewart over his shoulder and dropping him down into the ring.

Don't worry, though, Stewart's fine! Pretty beaten down and probably ready to start his retirement for realsies this time, but totally fine.

Well, for now, at least. This is the WWE, after all -- you never know what's going to happen next.