Declaring "I am in command of this ship," Damon not only hijacked the show Thursday night, but he brought along a little big-name help.
Ben Affleck, Jennifer Lopez, Nicole Kidman, Demi Moore, Amy Adams, Sally Field, Robert De Niro, Don Cheadle, John Krasinski and Oprah Winfrey all played a part.
Andy Garcia sat in as sidekick. Sheryl Crow led the band.
And where was Kimmel? Oh, he was there, all right: gagged and tied on the back of the set, as Damon took over.
"Just for starters," Damon told the ecstatic in-studio crowd, "let me ask you guys this: As an audience, is it weird to see a person with actual talent host this show?"
Admitting he'd been waiting a long time to do this, Damon – before turning his monologue over to Robin Williams – struck a personal note and said, "This is like the time I lost my virginity, except this is going to last way longer than one second."
Damon, tongue planted firmly in cheek for this all-star publicity stunt – earlier this month, Kimmel's show was moved into direct competition with CBS's David Letterman and NBC's Jay Leno – explained the basis for the Kimmel-Damon feud. The comic always wanted to be an actor, claimed Damon.
"I beat him out for every role he ever truly wanted," said the Bourne series star, now starring with Krasinski in Promised Land. "Jimmy has auditioned for every movie I've ever been in, every single one of them. How many did he get? None. So, he hates me."
Then there was the matter of Kimmel's ex, comedian Sarah Silverman, who in 2008 memorably sang a song about cheating with Matt Damon. (Kimmel retaliated at the time by saying he was "dating" Ben Affleck.) Silverman just happened to be Thursday night's guest.
"Is there anything you'd like to say to Jimmy?" Damon asked her, with Kimmel still held firmly in place, squirming. "He's a captive audience."
Replied Silverman: "No, I'm good."