Holyfield Frazier and I think Floyd Patterson deserves a mention. Usually the smaller man . He rematched guys that beat him badly, got up from A LOT of knockdowns. His late career efforts esp impress me. Had his chin matched his heart I think he would have been another holyfield
I don't see how it can be anyone other than Jack Johnson for stepping in the ring with Jeffries, surrounded by a literal lynch mob, not knowing if someone was going to pull out a gun and shoot him during the match. It is one thing to get off the mat 6x after being clobbed by a young George. It is another to walk into the ring knowing full well you may be literally assassinated.
Riddick Bowe forgetting the whole Lewis incident, I'm talking about inside the ring. He took inhuman punishment vs Golota in their 2nd fight, I can't think of many fighters who would of took 72 punches in a single round vs 240+ Heavyweight, and taking 400+ punches overall. Another one is Danny Williams, all I'm going to say is Mark Potter enough said.
Bowe had plenty of heart. That belt/Lewis incident showed he didn't have much for brains, mindless follower of dirtbag Newman.
Da Preem- Time and again, getting up from Bears onslaughts , lesser men would have stayed down, and not be chastised , not Carnera up he got to face more of the same, not only the physical abuse, but Max was cruel with fists and tongue. stay safe guys.
Williams against Potter. Forgot about that one. How Danny boy kept on and actually came back to stop him!? Mad.
He was being assaulted outside the ring quite often prior. After a fight over a towl lending incident a local featherweight glassed him with a bottle from behind.
One small caveat Primo asked the referee to stop both the Baer and Louis fights.That isn't a reflection on his courage he kept getting up didn't he,it's just an observation.Carnera certainly showed more heart in those fights than Baer did against Louis.