Real life royalty squares off against a Park Avenue Princess!

PHOTOS: Gossip Girl's best style moments

Duchess Catherine Middleton turned heads Thursday when she showed up at the ARK 10th Anniversary Gala dinner in a dazzling Jenny Packham gown -- the same one worn by Blair Waldorf, Leighton Meester's Gossip Girl alter-ego, during the show's fourth season.

Tell Us: Who wore Jenny Packham better?

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