Name an offnight for a great fighter: in which fight? What happened to throw him off?

What was the definition of an off night for a tough fighter?

I will go with Ricky Hatton vs Pacquiao. Hatton said coming into the ring he knew he was over trained and that his only hope was to go for the knockout. Well, he said "I tried, but several punches later I got sent to the canvas." In a devestating ko to the pacman.

Would things have gone differently? Or like Freddie Roach said (about Hatton) " for somebody who was supposed to be great, he wasn't that good."

This defeat sent him spiralling down, would it have been different if he did not overtrain or is Freddie right that PAC was on another level?.

Example two: John Ruiz vs rjjr. Ruiz was going through a divorce, the ref had an agenda against him, and he was being disrespected by boxing Insiders for all his holding. He said post fight "it was weird you know what I mean? I was fighting Roy and the ref in there". Also Roy commended him saying John's heart was probably broken too, unless I have mah facts wrong about the timing of his divorce. Maybe it was during the toney fight I'm not sure. That's why I'm posting it on classic because it's been so long!

What are your definitions of an off night for a tough fighter?