02/14/2012 11:39 am ET | Updated Feb 14, 2012

Jimmy Kimmel Shuts Down Jay Leno Over Toupee Joke (VIDEO)

Looks like the ongoing Jimmy Kimmel/Jay Leno feud has escalated.

Last Thursday, Leno offered some Valentine's Day gift ideas on "The Tonight Show," and one of the gags was a blanket made up of celebrity hairpieces. "There's even a Jimmy Kimmel! It's still got the black dye on it!"

Kimmel seemed mostly amused that Leno considers Kimmel such a threat that he'd go out of his way to make the joke. Kimmel even replays Leno's clip in slow motion to mock the "look what I did, ma!" grin that Leno bears when finishing the bit.

Of course, Kimmel and Leno's history, full of camaraderie and conflict, goes back far. According to Bill Carter's "The War For Late Night," they became friendly during the WGA Writer's Strike, when both their shows were off the air. However, the friendship was not permanent. Kimmel made headlines in 2010 during the Conan/Leno "Tonight Show" fiasco, when Kimmel did his show in full Leno get-up to poke fun at the host, who he perceived as stealing the "Tonight Show" back from its then-current host Conan O'Brien. After that, he appeared on "The Jay Leno Show" to tell Leno to his face what he really thought of his actions.

But on a recent episode of "WTF with Marc Maron," Kimmel revealed that more went on behind the scenes that resulted in Kimmel lashing out at Leno publicly. "I was working [at ABC], and there was a good chance Jay Leno was going to come to ABC," Kimmel told Maron, referring to the brief moment after "The Jay Leno Show" was cancelled and Leno was deciding what his next career move would be. "We had many, many conversations. And as soon as he decided to stay at NBC, those conversations were gone. And I felt kind of stupid, because I realized at that point, I [had been] been worked over."

While talking about Leno's "toupee" bit, Kimmel seems mostly amused, and once again launched into his Leno impression, rattling off some Leno-style monologue jokes with a lisp and instructing his house band to throw in grunts of encouragement like Leno's band. He then "proved" once and for all that his hair -- and its color -- are all natural.

Interestingly, Kimmel is a well-known devotee of David Letterman, who was also the butt of hairpiece jokes in the late '80s and early '90s (although he did not wear one). So perhaps Leno was unwittingly comparing Kimmel to his other late night rival -- a great compliment to Kimmel.