At least six men were involved in a wild punch-up after Thursday night's season-opening game between Richmond and Carlton at the MCG.
In disappointing scenes for the AFL, a brawl broke out on the ground level of the Great Southern Stand after the Tigers posted a 33-point win.
Video of the fighting showed one man, who was wearing a Richmond jumper, knocking out another man with a huge right handed punch before following up with three more blows to his fallen foe.
Other vision uploaded to social media (which you can view in the video player above), which was filmed from the grandstand overlooking the action, showed a policeman making a belated arrival to the scene.
Victoria Police told the Herald Sun a 19-year-old man was arrested. "It is alleged a fight broke out between a number of males inside the stadium just before 10.30pm," police said.