You may remember Andrew Shaw's header goal from last season's playoffs that was disallowed on the grounds of this sport clearly being hockey, not soccer.
Well, Jason Chimera had the answer to that no-goal with a legal version of his own!
Chimera and the Capitals can get away with this thanks to one key element: It was purely accidental. Marc-Andre Fleury tries to poke the puck away from Chimera on partial breakaway, except it rebounds off of his stick and into the noggin of the Capitals forward. From there, physics takes over and it loops over the Penguins goaltender's head and into the net.
See, you can headbutt pucks into the net! Just not on purpose, of course.