Calling all high school football referees! Let the above video be a lesson -- keep your eye on the ball at all times! 

The video comes to us from Allentown, Pennsylvania as the Dieruff High Huskies face off against the Pocono Mountain East Cardinals in the opening game of their respective seasons.

Huskies quarterback Quintin Williams was trying to hit an open receiver near the end zone, but he ended up throwing the pass over both the wide receiver and the defender's heads. What Williams did hit, however, was the head of the side judge trying to watch the play unfold.

Heads up, ref!