Nate Diaz, Jorge Masvidal Press Conference Ends In Wild Brawl

6/7 -- 10:20 AM PT -- TMZ Sports talked to Jorge Masvidal's boxing coach Jorge Capetillo -- who was front and center (JC was rockin' the burgundy t-shirt) when things kicked off on Thursday -- and we asked him about the brawl ... including what led up to the melee, and whether he's okay after the fight.

Nate Diaz and Jorge Masvidal don't fight for another month, but the action was well underway at their press conference on Thursday ... with "Gamebred" getting in the middle of a violent scuffle.

It all went down in Anaheim just minutes ago ... shortly after Diaz stormed off the stage without doing a ceremonial face-off with his opponent.

It's unclear what sparked it all -- we're assuming trash talk -- but in a video of the fracas, Masvidal is shown slapping a man's hand down -- and then the fists started flying.

It appears both fighters' crews were doing the most of the damage to each other ... with one guy taking a tumble into the seats and knocking the entire row over.

A voice is heard yelling for security to secure Masvidal ... but the chaos seemed to continue for at least a minute.

At one point, a member of Diaz's entourage was chirping pretty heavily toward Masvidal ... calling him a bitch.

Eventually, cooler heads prevailed ... or at least that's what we thought -- but when Nate and Jorge saw each other inside after the brawl, they started yelling at each other from across a hallway.

The real fight goes down July 6 ... that is, if these guys don't cross paths before then.t