Britney Spears Takes the Stage in Las Vegas

Thrilling fans in Las Vegas late Friday night, Britney Spears and her dancers performed three 'Femme Fatale' songs for an MTV special promoting the album, which officially drops Tuesday.

It was a mini-concert, to be sure, but was her first live show since the 'Circus' tour in 2009.

Spears, 29, wore form-fitting black leather, according to Us, and wowed the crowd at the Palms Casino's Rain nightclub, singing "Hold it Against Me," "Till the World Ends," and "Big Fat Bass."

According to People.com, her set lasted approximately 45 minutes, with 'Jersey Shore' star Pauly D (resident DJ at the Palms) helping to keep the crowd of more than a thousand fans on their feet during Spears' short breaks for costume changes.

All week, the surprise performance had been kept under wraps, but when news leaked Friday that she'd be taking the stage, Spears decided to go ahead and confirm it on Twitter:

"Looks like my little secret isn't a secret anymore...Who's coming to watch me take the stage?" she tweeted, adding, "You're all invited. Be there or be square b--ch!"

She even posted a coy Twitpic of the Palms Casino Resort marquee which advertised 'DJ Pauly D & Special Guest.' Spears

While she performed Friday for the Vegas crowd, her father, Jamie Spears, and her boyfriend, Jason Trawick, reportedly watched from a VIP area as the performance ended with fireworks.

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