If you're going to go for a KO, then you might as well make it a spectacular one...
These two fighters, taking part in the PPO Karate Championships in Ulyanovsk, Russia, were competing under shinkyokushin rules.
For those unfamiliar, that's a form of karate which only allows blows to the head from the leg or the foot. And for one of these fighters, that's the most impressive way to make an impact.
Watch the remarkable video below: