Pat McAfee's "Big Night Aht" event turned into a fight club in one section Wednesday night in Pittsburgh ... 'cause some yinzers started going at it in the crowd -- and the whole thing was caught on video.
While it's unclear what sparked the scrap, multiple parties were involved at PPG Paints Arena. At one point in the chaos, a man in a black shirt tried to break things up before getting sucker punched by a guy in a plaid shirt.