Usher joins Justin Bieber onstage

Usher thrilled Justin Bieber fans in Georgia on Wednesday night (13Apr16) when he showed up for the pop star's Atlanta gig.

The Baby singer's mentor joined Bieber onstage for an acoustic rendition of his 2001 hit U Got It Bad, and then the pair teamed up on a medley of Usher songs, including I Don't Mind and U Don't Have To Call.

After the show, Bieber took to Twitter to thank the Yeah! hitmaker and Akon, who also briefly hit the stage with the headliner.

He wrote, "That was one of the best yet. Thank you to big bros @Usher and @Akon for coming out. Made Ush play all the hits."