A "top secret" was revealed on David Letterman's Top 10 List Monday night – the identity of the cover girl for the 2011 Sports Illustrated Swimsuit Issue.

Irina Shayk, 25, the first Russian model ever to grace the cover of the iconic annual swimsuit issue, was overcome. "There were ten models there to do the Top 10 List, and nobody knows until the last minute who the cover will be," she said after the curtain fell over her billboard in Times Square. "And then I saw it, and I couldn't believe it."

Though Shayk has appeared inside the swimsuit issue every year since 2007, being the cover girl introduces her to an whole new league. Shayk, who is dating Portuguese soccer star Cristiano Ronaldo, joins the ranks of such supermodels as Christie Brinkley, Heidi Klum, Tyra Banks, Rebecca Romijn and, most recently, the Just Go With It actress, Brooklyn Decker.

The 2011 SI Swimsuit Issue hits news stands February 15. —KIMBERLY STEELE

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