Huge Brawl Breaks Out At Crypto.com, Fan Knocked Out

The Lakers and Mavericks weren't the only ones battling on Tuesday -- fans outside the arena duked it out, too ... with a massive brawl breaking out and resulting in a man getting knocked out.

The chaotic scene unfolded the same night the Lakers beat the Mavs 107-99 at Crypto.com Arena in downtown Los Angeles ... the first time Luka Doncic had to face his former team since the blockbuster trade.

In a clip of the madness, a man in a LeBron James Lakers jersey appears to be taking hits from a group of angry fans ... but recovers to the point where he tries to go after different enemies one at a time.

He gets hit with some more punches and ends up on the ground ... but with credit to the dude's toughness, he stumbles back to his feet for more.

Eventually, he gets hit with a knockout punch that flattens him on the ground.

As all this unfolded, other fights broke out as well ... but everyone scattered when officials arrived to de-escalate the situation.

LAPD told us no arrests were made from this incident, but a felony battery report was completed.