I think it was the Hatton KO. Just because I was there and actually heard the 'THUD' sound that the shot made. I swear, you could feel/hear that shit inside the noisy ass arena.
That was one of the most brutal one shot KO's of all time. One punch KO's are way more impressive than cumulative KO's where the guy is already on rubber legs...
The one that just comes out of nowhere and just lights out.