Brawl Breaks Out In Stands During USA Vs. Mexico World Baseball Classic Game

The field wasn't the only thing seeing action during Monday night's World Baseball Classic showdown between Mexico and the United States of America ... a brawl broke out in the stands between fans of the two countries, and it was ugly!

The fight went down in the outfield seats at Daikin Park in Houston, and was captured on video. The clip shows a man in Team Mexico gear running up on another man rockin' Team USA swag, before the two start swinging on each other.

While we don't know what kicked off the festivities, both sides landing solid blows -- with the supporter of the red, white and blue taking a nasty tumble down the stairs at one point.

Unfortunately for a guy in an Aaron Judge shirt, he got caught up in the crossfire -- getting knocked over from behind and falling down a row.

Once the USA supporter got back to his feet ... he wasn't going to walk away without getting his lick back -- landing a clean blow to the left side of the face of one of the men.

He even brought backup of his own, and more people tumbled down the stairs.

Peace was eventually restored ... but it's unclear whether there were any ejections or arrests.

While it's up for debate who won the fight off the field, on it ... it was Team USA who beat Mexico, 5-3, remaining undefeated in pool play.