NHL Fan KO'ed During Brawl At Anaheim Ducks Game, Cops Investigating

A fan at the Anaheim Ducks game on Friday night appeared to be knocked completely unconscious during a wild brawl ... and now, cops say they've launched an investigation into the matter.

The fight broke out as the Ducks took on the Winnipeg Jets at the Honda Center ... when a group of fans who were reppin' opposite teams got into it with each other right in the middle of a concourse.

You can see in video from the scene ... a man in a Jacob Trouba Jets jersey broke off from the squabble and began tussling with a guy in purple Ducks jersey.

During their ensuing wrestling match, the Winnipeg fan slammed the Anaheim supporter to the tile floor using a leg takedown maneuver ... appearing to leave the man KO'ed.

The guy lay motionless for several moments ... before he rolled over in what seemed to be a heap of pain.

The Anaheim Police Dept. said in a statement to TMZ Sports officers were dispatched to the area after the tilt had gone down ... and one person was transported to the hospital with a head injury.

"The investigation is ongoing," a spokesperson for the department said, "and no arrests have been made."