Jimmy Fallon & John Rich's 'Drunk On Christmas' Hits iTunes

Jimmy Fallon is known for performing memorable duets with music stars on NBC's "Late Night with Jimmy Fallon" ( "Whip My Hair" with Bruce Springsteen and "A History of Rap" with Justin Timberlake, to name a couple). But for the first time, the funnyman is putting a collaboration from his late-night show up for sale.

"Drunk on Christmas," a song that Fallon originally released as a solo single last December, is now on available on iTunes in the form of a live duet with country star John Rich, who performed the track with Fallon during an episode that aired last Thursday (Dec. 16).

Video: Jimmy Fallon & John Rich perform "Drunk On Christmas"

"That's why I'm drinkin', drinkin', drinkin', I'm gonna drink all day," Fallon and Rich sing on the holiday tune, which was co-written by the host with longtime friend and "Late Night" writer Gerard Bradford. "I'm going home for Christmas and my family's insane/Just gotta make it through the day, and there's no other way/Gonna get drunk, drunk, drunk on Christmas."

Of course, "Drunk on Christmas" isn't Fallon's first foray into selling music. The former "SNL" star released his own full-length album, "The Bathroom Wall," in 2002 (which also featured writing collaborations with Bradford), as well as the charity single "Car Wash for Peace" in 2007, to benefit military families.