By Breaking Celebrity News Staff

Las Vegas goes crazy for Labor Day weekend, and none othe than Will.i.am kicked off the party Friday at Encore Beach Club at Encore Las Vegas.

Hundreds of fans were treated to a performance by the singer and his Black Eyed Peas bandmate apl.de.ap.

Nicole Scherzinger -- the Pussycat Dolls lead singer-turned-judge on Simon Cowell's new The X Factor -- was so moved that she joined the superstar musician in the DJ booth and showed off some of her sexiest dance moves.