Michael Spinks was defeated before he even entered the ring against Tyson.
Clottey put his earmuffs on against Pac, too scared to fight.
Neither Mayweather or Pac showed up for their flop.
But as far as fighters just not showing up on fight night, can't say I recall. Several fights have been postponed for illness or injury, but can't recall one on fight night.
it doesnt happen that often on the big stage, but at the club show level its not that uncommon. Ive had guys get sick, get arrested, even had one opponent not show up to the weigh in and when we called him he said he got called into work lol.
Sure, the commission will usually suspend their license for 6-12 months for pulling a no-show, but that doesnt help you any when a fight you had on your show falls out at the last second......
There's a possibility that some of the last minute illness/injuries have been essentially no-shows. These guys have too many handlers and appointments to just disappear. They're constantly expected to be at a certain place at a certain time so sudden illness or injury is the only way out.
I don't know of this happening in boxing a lot but it's happened a number of times in MMA. The night Kimbo was first KO's, Ken Shamrock was reportedly holding them up for more money and when they wouldn't give it to him, he suddenly got injured and couldn't go out.