A violent fistfight broke out in the stands during the USA vs. Mexico soccer game Sunday night -- with fans throwing haymakers left and right ... and the wild scene was all captured on video.
It happened at some point during the United States' 2-0 win in the CONCACAF Nations League final at AT&T Stadium in Arlington, Texas ... when Team Mexico fans had clearly had enough of a gloating US supporter.
Check out the footage ... as the man decked out in red, white and blue cheered on his squad -- a Team Mexico fan tried to sock him in the face.