A Las Vegas Raiders fan had a really rough Sunday afternoon in Los Angeles ... his team not only lost to the Chargers -- he was socked in the face by a huge haymaker while attending the game.
The Howie Long supporter was decked after he got into a spat with a Justin Herbert fan during the Raiders vs. Bolts tilt at SoFi Stadium ... and the wild fight was all captured on video.
You can see the fracas appeared to start when the Long supporter got into the face of the man in the powder blue jersey.