Jake Lamotta. And that's not a knock on Jake, who I consider a solid fighter, but his name is incredibly huge from the movie and fighting SRR, and what did he really do? He won the World Title with a spectacular come from behind KO in a fight he was losing handily (for the vacant world title, so he never even beat a champion to get it), then he lost the title in the very next fight by savage SRR beating.

Good but over rated fighter. Book and movie thrust his name value higher than his fighting ability did.