An all-out brawl nearly erupted during the Astros vs. Mariners tilt on Wednesday night ... and according to one Seattle player, it all started 'cause Houston pitcher Hector Neris called Julio Rodriguez a homophobic slur.
The near-dust-up on the diamond went down in the sixth inning of the Astros' pivotal game with the Mariners at T-Mobile Park ... after Neris struck out Rodriguez with a breaking ball.
The reliever was so pumped to get the Seattle superstar out, he charged at him .