While being showered with chants of "Uh vai morrer" -- which roughly translates to "You're gonna die" -- Brown flipped the bird to the fans at the Arena da Baixada in Curitiba, Brazil. He then turned his back to the crowd and flipped one more double bird, just for good measure.
The actions prompted a cutaway by the cameras broadcasting on FOX Sports 2, but uncut video can be seen below.
Brown (20-13) officially weighed in at 171 pounds. He is the No. 8 ranked welterweight on the UFC's media-generated rankings and fights Demian Maia in a pivotal clash this Saturday at UFC 198.
That bout headlines the preliminary portion of the card and is scheduled to air live on FOX Sports 1.