Usher closed out the iHeartRadio Festival with an exciting 20-minute set in Las Vegas on Friday (Sept. 19). The R&B crooner also surprised audiences by bringing out his good friend and 'New Flame' co-star Chris Brown.

Usher took a moment during his set to introduced Breezy whom he described as his brother and friend.

"I'd like to introduce this young man that I've gotten to know," he told the crowd (quotes courtesy of Billboard). "He's a friend, he's a brother, he's a passionate artist and I have a fortunate opportunity to have shared a song with him."

Brown then appeared to sing his vocals on 'New Flame,' much to the crowd's delight. Usher then followed with his lyrics and then challenged Brown to a dance-off.

The two performers showed off their fancy footwork with Brown slightly outshining the veteran singer. Not to be outdone, Usher pop-locked and spinned across the stage before setting his Air Jordan high-top ablaze, hence the song 'New Flame.' In a sort of weird way, it could also mean that Usher was passing the torch to Brown.

Nevertheless, it was a fiery performance between the two R&B superstars.

Prior to the dance-off, Usher performed his recent singles 'Good Kisser' and 'She Came to Give It to You' (sans Nicki Minaj).