I know, just a slip and one right hand later and he didn't get up.

Not sure if anybody else has repeated it yet, I've only had a few one punch Kds since but no one punch KOs.

I cheated to get the 'just like mike' acheivement (you have to KO them in one round) but I did it against a middleweight and I had to knock them down twice to get it... (I picked a random one... I may as well have picked a heavyweight... La Motta's chin is like 97 or something... maybe the highest in the game?)