Not a lot is known about the circumstances of this goal celebration in an amateur Italian football league.
What is to know (and it's all you need to know):
Player scores a soft goal off of a set piece and a goalkeeping blunder. Player decides to celebrate by head-butting the glass. Player's head surprisingly defeats the glass. Player gets sent off by the referee (to player's surprise).
Hilarity ensues all around.
Hat tip to 101 Great Goals for the find.