Jimmy Fallon, Zach Galifianakis Switch Spots in 'Late Night' Interview Goof (Video)

Lloyd Bishop/NBC

When you've got two world class talk show hosts on the same stage, something has to give. And like a gracious hometown host, Jimmy Fallon agreed to make way for Zach Galifianakis -- for the most part, anyway.

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With Galifianakis in town to promote his upcoming political farce The Campaign, the two funnymen switched sides of the desk for a segment that rang more than just a little bit like the bearded star's hilariously uncomfortable web show, Between Two Ferns. Taking it one step further, Fallon played the role of Galifianakis, and Galifianakis (as Fallon!) peppered him with irrelevant, half-baked questions about his flight, his weight struggles, and what it's like to work with Will Smith.

Obviously, he meant Will Ferrell.

Galifianakis will play much dumber in The Campaign, in which he stars as a dimwitted local who gets coaxed into running for Congress against a superslick, yet gaffe-prone, representative, played by Ferrell. The film hits theaters on August 10.