Wardrobe malfunctions happen to the best of us, even Britney Spears. The pop star's "Piece of Me" concert almost got a little too risque when her costume flew open during Saturday night's show. Spears was performing "Circus" when her costume's zipper opened up, exposing her back.

Britney didn't miss a single beat though, as her backup dancers rushed to zip up her costume, and the piece carried on with hardly any interruption at all.

Spears has just begun a two-year Las Vegas residency with her "Piece of Me" show at the Planet Hollywood Resort & Casino. The show is receiving rave reviews and the opening night was attended by many stars, including Miley Cyrus, Katy Perry, and Mario Lopez. She was recently criticized for lip-syncing during performances, but many reviewers say that all in all, the show is a success.

Casino executives say the residency may be extended past its two-year slot if it is successful.