Chicago Bears Fan KO'ed By Haymaker In Violent Fight At Game

A Bears fan was hit so hard by a haymaker during a fight at Chicago's game over the weekend, he appeared to momentarily lose consciousness right in the middle of a stadium concourse.

The wild fracas happened at some point during the Bears' tilt with the Vikings at Soldier Field on Sunday ... when a group of men became so enraged with one another, they started brawling.

At one point during the action, a man in a Walter Payton jersey was absolutely leveled by a Justin Fields supporter ... and you can see in video from the scene, the punch seemed to briefly KO the man.

Somehow, however, he got up -- before he was pushed back to the ground just seconds later.

Meanwhile, as several other Bears fans were scuffling, a man kicked another man hard in the head. The violence then appeared to mercifully stop.

We've reached out to cops to see if any arrests were made, but so far, no word back yet.