The Billboard Music Awards got off to a red-hot start tonight as Rihanna took the stage for a performance of 'S&M' that included a surprise appearance by Britney Spears.

Rihanna, dressed in a skintight white outfit, got things started by rising from a chair to prance around the stage with a number of sultry moves. About halfway into the performance, Britney shot from the depths of the stage to appear in a black bondage suit with a a bunny-eared mask.

Brit Brit then began contributing her part to the popular 'S&M' remix before flipping off her mask, as the two pop sirens made their way over to stripper poles where they delivered mirroring dance moves.

Overall, it was an incredible performance by both singers, and an amazing way to kick off the show. The two received a rousing ovation from the Las Vegas crowd.

Watch Rihanna and Britney Kick Off the Billboard Music Awards With 'S&M'