Chris Brown joins Justin Bieber on stage

Justin Bieber’s Australian concertgoers were in for a surprise last night (April 28), when the pop star invited Chris Brown to join him on stage for a duet, reports Teen Music.

Just as Bieber was finishing up his solo song With You, Brown swept out onto the stage to the delight of fans, and joined the pop star in singing their collaborative single, Look at Me Now.

Last week on Twitter, Bieber had hinted to fans that he had something special planned with Brown, leading many to speculate that there might be a duet performance in the works for one of his shows.

The first surprise for Australian fans, however, was that there was a concert at all. Rumors suggested that the show would be cancelled after Bieber injured his back wake-boarding in Indonesia last weekend. The pop star reportedly defied doctor’s orders and insisted that the show must go on.

"I don’t cancel…In route to Sydney!! THE SHOW IS ON!! I don’t let my fans down!" Bieber tweeted on Wednesday (April 27).