LMFAO closed the 2011 American Music Awards show with an unforgettable performance featuring Justin Bieber helping out with the dance moves!
LMFAO started out singing "Party Rock Anthem" with Justin making an appearance on stage toward the end, Entertainment Weekly reports.
"Go, Bieber! Go, Bieber! Go, Bieber!" they shouted.
The 17-year-old "Mistletoe" singer rocked the stage in a "SEXY" T-shirt and Zumbaz pants. His girlfriend, Selena Gomez, cheered him on from the audience!
And while Justin may be sexy and knows it, he ran off the stage when "Sexy And I Know It" came on and let a new guest take over.
David Hasselhoff, wearing smiley-face underwear, came out to dance.
"We love you party people! I want to wiggle with David Hasselhoff!"
We're not sure we wanted to see that, though!
Watch the performance in a YouTube clip, HERE!
What did you think of it?