This Brutal 'Knee to the Head' Knockout Would Have Been Illegal in America

Knees and kicks to the head of a downed opponent are expressly forbidden under the unified rules of MMA...but not all organizations compete using that set of regulations.

Singapore's One Championship is one of those exceptions, and that can, occasionally, result in particularly vicious knockouts that wouldn't be legal in American promotions. 

Zebaztian Kadestam scored one such knockout on Friday at One Championship: Dynasty of Heroes at the expense of Brazilian vet Luis Santos. Check it out above (h/t MMA Fighting).

While the strikes weren't explosive, short knees like that can do serious damage, a fact known to many fighters that have competed in Asian promotions. Santos, thankfully, was able to walk away under his own power but this is a good reminder of how devastating these strikes can be.