Video from inside the stadium shows a violent brawl that broke out between a group of home fans in the stands. The footage captured men and women trading blows.
One of the men in the video shoved a woman down the bleachers while holding a beer. A security guard eventually arrived and broke up the fight.
It's not clear what prompted the violence or if anybody was arrested.
Meanwhile, New York's offense never managed to get going against San Francisco's tenacious defense. The 49ers won 30-12.