Jon Stewart hosted the WWE's "SummerSlam" pay-per-view last night and he even got involved in the action.

In a surprise move, he actually turned heel and helped his former enemy Seth Rollins retain the WWE World Heavyweight Championship in his match against John Cena.

With the referee knocked unconscious, Stewart ran to the ring and hit Cena in the gut with a folding chair. He then put the chair on the mat, so Rollins could smash Cena's head against it with The Pedigree. Rollins went on to win the match, walking away with the World Heavyweight Championship and the United States Championship.

(Photo by JP Yim/Getty Images)
(Photo by JP Yim/Getty Images)
(Photo by JP Yim/Getty Images)
(Photo by JP Yim/Getty Images)
(Photo by JP Yim/Getty Images)
(Photo by JP Yim/Getty Images)