and sometimes , but rarely , one of the fighters would display real skill ; the sort of wrestler who used his opponent 's weight against him , who could nonchalantly turn out of the way of a haymaker and hook a negligent foot under his enemy 's knee , and watch him fall , almost as if surprised by the success of the tactic , or who could somersault over an attack , roll over to come back up instantly on his feet , and then deliver a perfect kick to the jaw .