Nathan Fillion has gone from little-known soap actor to the lead star in a hit primetime TV show, 'Castle.' Still, the handsome Canadian is used to going unrecognized when he walks down the street ... or even when he presents an award at a major music awards show.

"I was at the American Music Awards, presenting an award to Lady Antebellum. They come up, accept their award ... they're very excited and I'm excited!" Nathan tells David Letterman. "But as I'm walking her (Lady A's Hillary Scott) off stage, she says, 'I have to tell you, I love your show. I'm so sorry it got canceled. I just loved 'Arrested Development.'' I said, 'Yeah, you think I'm Jason Bateman. I'm not.' She said, 'I'm so embarrassed! I said, 'How do you think I feel?' [laughs]"

No need for Hillary to be embarrassed. Nathan admits he gets mistaken for the 'Arrested Development' star a lot. In fact, they even poked fun of the resemblance on a recent episode of 'Castle.' (Watch the clip below.)

'Castle' airs Mondays at 10:00 PM ET on ABC. As for Lady A, they are basking in the glow of yet another trophy to add to their crowded mantle. The trio took home the Artist of the Year: Duo or Group honors at Monday's American Country Awards. They're also celebrating the recent announcement that their third studio album, 'Own the Night,' certified platinum (signifying sales of more than 1 million) in just four weeks.



Watch the Jason Bateman Joke on 'Castle'

Watch Lady A on the AMA Red Carpet

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