The Las Vegas Bowl was on the verge of an all-out brawl in the crowd, but after the punches started flying one man stomped out the fuse with a colorful threat.
Ya gotta see the video ... Arizona State fans are jawboning each other in the stands at Allegiant Stadium and the Sun Devil on Sun Devil crime escalates to some haymakers.
Then, a Wisconsin Badgers fan runs over and lays down the law ... putting his fingers in the ASU supporters' faces and telling them he'll knock them out cold if they don't cut the crap.
Folks who nearly had a front-row seat to a much bigger fight roar in approval after the Wisconsin fan silences the trash talkers ... and both fan bases bond over a "Let's Go Badgers" chant.
The Wisconsin fan saved others a headache ... we're told police and security didn't come to the section, and this all happened midway through the 4th quarter.
As for the game ... Wisconsin beat ASU, 20-13.