If you only watch one karate kick knockout all day, make it this one.
This video comes from the PPO Karate Championships in Ulyanovsk, Russia, where the fighters are apparently competing under Shinkyokushin rules. That means there's no protective gear, and blows to the head are allowed with only the leg or the foot.
After some sparring, one of the fighters decides to make quick work of his opponent with an extremely athletic kick to the neck.
This looks like it hurt.
You've got to love the confidence in this guy. Not only does he attempt this extremely risky move, afterwards he gets up and walks away looking like he just won the lottery.