How about the guy that Haye faught on his debut? [ame]http://www.youtube.com/watch?v=OXuBML8C61c[/ame]
In all fairness when he clapped those gloves together and hit ruiz with his first punch when he went down like a sack of spuds i thought that was game over but Ruiz proved tougher
I've only ever seen one punch knockouts in the pub, never in the ring. The softening up process prior to the KO is an intrinsic part of that knock out so there is no "one punch" about it.
I think he just has accumulative power, like Pavlik opposed to the one punch power like Hearns or whatever. More pop than bang, if you will.
You could say the same about most fighters. Lennox Lewis, for instance. Other than Rahman I can't recall a stone cold out of the blue, flat on his back KO. Haye has big one shot power, hence his punches causing major damage early.
He's just very heavy handed. Tends to stun the opponent then rains blows down on them usually clubbing the poor guy to the floor rather than knocking them out. He likes fighting people too much.