Former contestant Ian Benardo, who was rejected at the audition stage during a previous season of the talent competition, ran onto the platform at the Nokia Theatre in Los Angeles and grabbed the microphone from Cook, interrupting his comedy skit.
Calling it "a Kanye West moment", Benardo began to hurl abuse at retiring American Idol judge Simon Cowell, insisting he was going to replace the music mogul on the show because "I'm more entertaining than you."
Cook took to his Twitter.com page to share his shock at the unruly protestor's behaviour, writing, "Weirdo hijacked the song. Just glad he didn't hit me in the face w/ (with) the mic or American Idol would b (sic) American Beatdown."
But Benardo, who grew up in the tough boroughs of New York, is refusing to take the "weirdo" comment lightly and has taunted Cook to fight him in the ring.
He tells the New York Post's gossip column Page Six, "After the show, Dane Cook called me all kinds of names. His publicist followed me out and kept calling me a stupid freak and that... I belong in hell. Then Cook went on Twitter and called me a weirdo.
"I was born in Brooklyn and raised in the Bronx. Where I come from we don't tweet about it, we do it. If he wants an American Beatdown he should come and face me in a boxing ring. I will beat him down."
Cook has yet to respond to the challenge.