Canelo Alvarez Rages in Vegas After Destroying Julio Cesar Chavez Jr.

What do you do after beating the living dog snot out of Julio Cesar Chavez Jr. -- YOU TURN UP IN VEGAS ... that's what Canelo Alverez did right after the fight ... and we got the pics.

Canelo was in a GREAT mood after destroying Julio in a 12 round beatdown in Vegas -- a fight that was capped off with the announcement he's fighting Gennady Golovkin in September.

So, with all that energy, excitement and money (to come), Canelo hit up Jewel Nightclub at the Aria Resort & Casino with his girlfriend Fernanda Gomez and raged all night long.

Canelo's promoter Oscar De La Hoya was there too -- and smiling from ear to ear -- because he's going to make a FORTUNE when Canelo and GGG throw down!!!