After picking a fight with another robot in a movie theatre, Bender accidentally knocks him out. The other robot turns out to be a professional fighter from the Ultimate Robot Fighting league and whats more it the fight was witnessed by a URF manaager.
He signs Bender as one of his fighters and Bender quickly becomes a crowd favourite. The league turns out to be fixed with the most popular fighter always winning each match, and when Bender is asked to throw his next match he turns to Leela to help train him so that he can win his next fight. Leela only agrees to help him when she discovers the other robots trainer is her old mentor who never really believed in her.