Wednesday was a day to forget for Cameroon. After Alex Song earned a straight red card in the first half for elbowing an opponent in the back, Cameroon was forced to play a man down for 50 minutes, and Croatia cruised. Mario Mandzukic (the recipient of the elbow) scored twice to put Croatia in contention to make the round of 16, and Cameroon failed to score for the second consecutive game.
In the 90th minute, Assou-Ekotto lost control and headbutted teammate Benjamin Moukandjo Pierre Webó ran over to break up the scuffle. Check out the headbutt in the series of screenshots below
Or better yet, here is an animated image of the headbutt