Any theories that a brawl in the Levi's Stadium bathroom just before Sunday's San Francisco 49ers/Kansas City Chiefs game had to do with team rivalry will be overturned by the below video of the incident, which shows a nasty bit of Niners-fan-on-Niners-fan violence. (We'll warn you, now: the video is brutal to watch, and there is harsh language clearly audible in the clip.)

Two men were arrested just moments after the beating, which happened just before 1:25 p.m. Sunday in a Levi's Stadium bathroom on the 300 level on the north side of the stadium, Santa Clara police Lt. Kurt Clarke says.

According to Clarke, two victims were transported the hospital following the altercation. Clarke did not know their condition as of Monday morning. Monday afternoon, Santa Clara police released a statement that read that “One victim was treated and released and the other victim is listed in serious condition.”

As you can see in the video below, a man in a Frank Gore shirt starts to pound a fan wearing a Colin Kaepernick shirt. The Kaepernick-garbed man goes down, almost immediately. The guy in the Gore shirt is then joined by a man in an Aldon Smith jersey, both of whom then appear to drag another man across the room and begin to beat him as he lays on the ground.

According to Clarke, two men were arrested and booked into Santa Clara County jail for the attacks, but he could not confirm that the men arrested were those in the video, nor would he release the identities of those arrested men. This afternoon, KRON4 reported that the duo are 34-year old Dario Rebollero and 27-year old Amador Rebollero, who "had fled from the restroom" before being placed in custody.

ABC7 reports, that this is the second assault reported since Levi's Stadium opened.

"We've had two incidents at the stadium," Clarke told ABC7. "One being a domestic violence assault, and now coupled with this assault right now, so we've had two assaults, slightly different as far as charges, but assaults they are."

Investigators are still looking into what led to Sunday's bathroom assaults, Clarke said, but video poster Alex. C might have a clue: According to him, the fight was "all due to impatience for an open stall." Nice.