Jamie Foxx is ready to perform on the drop of a dime — proven in his impromptu singing of one of his most famous songs … which had an assist from Diplo.

The comedian hit XS Nightclub in Vegas Friday, rolling in around 3 AM with a large crew and joining Diplo — who was DJ’ing — onstage. Seems he was in the mood for a classic … diving into his and Kanye‘s smash hit, “Gold Digger,” as if it was 2005 all over again.

It’s pretty cool to see Jamie belting out his old ditty … dude hasn’t lost a step, and people definitely haven’t forgotten it either. They were singing along word for word. We’re told Jamie stuck around a bit longer to help sing “Rack City.”

JF wasn’t the only celeb to pop in either … Imagine Dragons’ Dan Reynolds also made a cameo at XS. He showed up almost at 4 AM, and he too waved to the crowd from Diplo’s elevated position. Dan also got on the mic a bit, but didn’t sing or anything.

Speaking of Diplo … he’s on a bit of a high right now. The guy recently won a lawsuit against a woman who was allegedly harassing him, scoring a massive judgment in arbitration.