Corden -- who has previously battled Helen Mirren, Samuel L. Jackson, Nicole Richie and David Schwimmer -- came out hard with the lines, "I heard I was battling an A-list hunk, but when I saw Ashton Kutcher, I knew I was getting Punk'd, you haven't had a hit movie since 2002, you were so bad in Jobs even Siri won't talk to you."
Kutcher, pretending to be hurt, came back with "People came to see Peter Rabbit battle me, but your battle's with your lady, her rabbit's out of batteries, my career's been doing fine ever since the '70s, your job's an uber driver for real celebrities."
The two went at each other with jabs at their career choices and looks, but in the end, Drop the Mic judge/Late Late Show house band leader Reggie Watts couldn't choose a winner, so he brought out Sean "Puffy" Combs to help decide.
"First of all, I want to say that was very entertaining," Combs said, after surprising the crowd. "In one of the closest battles in The Late Late Show history, the winner, by only a half a point, for the very first time in history -- James Corden."