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The setup: Apparently Matthew McConaughey likes to take his shirt off, even ferreting out cinematic opportunities to bare his chest. So says Matt Damon in a pitch-perfect impersonation of the ever-so-subtle Texas twang of the alliteratively named screen star and former Sexiest Man Alive. Mr. Damon appeared Dec. 11 on CBS’s “Late Show With David Letterman” to promote his upcoming movie “The Good Shepherd” and delivered his dead-on Mr. McConaughey imitation at Mr. Letterman’s request.

The source: CBS posted the clip Dec. 11 on YouTube.

The hits: The video reached more than 674,000 views by Dec. 14.

Video: Mocking Matthew