Did you miss the rest of the fight where Cain was throwing him around like a rag doll at will and JDS couldn't do anything to stop it?
People used to say Cain had a glass chin, then JDS knocked him out. Derp derp it must be true. No they are fighting at the highest level against the best heavyweights around. If JDS had clocked Cain with a similar punch to the first fight he wouldn't have been ragdolling him. WHen these guys hit big it usually changes the course of the fight be it a KO or a zombie opponent