Not only did the San Francisco 49ers lose to the Arizona Cardinals on Sunday, but a number of their fans found themselves at the center of a messy, gory fight that sent a crowd over several rows of seats and down the stairs.

University of Phoenix Stadium security can be seen struggling with the brawlers in the video below, which captures a scrum caused by, the videographer says, "a mixture of alcohol and a heated rivalry." After the dust clears, the miscreants appear to have been ejected, and the scene of the crime is dappled with a spatter of blood. Good job, everyone. You're all very manly.

Related: Daisy Does the Niners: 49ers Fall Apart in the 2nd Half. Again.

Update: while the YouTube user who uploaded this video we originally had embedded below has since removed it, they didn't do so before KTVU snagged it. Good work, KTVU!