It boils down to fighting, sure technique is important, but you better be sure your technique can conquer sheer size, speed, and talent. God hands out gifts to some people, Lesnar might just be one of those people. Call mixed martial arts, I don't care, but I will call it by it's real name and that is fighting. Right now Lesnar is the best fighter in the UFC's heavyweight class.
Low kicks, Lesnar likes to hit takedowns off of low kicks. Right now no one stops Lesnar from taking them down.