James Corden punk'd Ashton Kutcher so hard, Diddy crowned him 'Drop the Mic' victor

Sure, The Late Late Show is James Corden's turf, so you could argue he has home-field advantage when it comes to a "Drop the Mic" throwdown. But when he challenged Ashton Kutcher to a rap battle Tuesday, the late-night host lyrically knocked him back to the '70s.

Corden had endless slams for his opponent who he described as "the tool who made trucker hats cool."

"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," he spit. "You do great charity work, year after year. Want to save something from dying? Start with your career."

Corden revisited Kutcher's acting career for the second round.

"Valentine's Day and New Year's Eve are movies you fumbled, you ruined more holidays than a Trump-loving uncle," he rapped. "You joined Two and a Half Men when producers intervened. It's the only time people thought, 'Man I miss Charlie Sheen.' You invested all your money in technology and apps. Hell, I'd do the same thing if I knew I couldn't act."

Kutcher went down swinging. “People see me at valet, they say, ‘Look, it’s a star,’" he told Corden. "People see you at valet, they say, ‘Dude, where’s my car?'”

The Ranch actor also ribbed Corden for his appearance. "I hate to kick a man when he's down in a slump, but I'm looking at the baby of Kim Jong-Un and Donald Trump."

Their battle left leader of the Late Late house band, Reggie Watts, wishing for an expert judge to decide a winner. Thankfully, Diddy was on-hand.

For the man formerly known as Puff, it was a close call, but he was able to settle on a champ. "In one of the closest battles in the Late Late Show history," he began, "the winner, by only a half a point, for the very first time in history, James Corden!"

See Corden and Kutcher's full face-off in the clip above.

WSBTV