Jack London 
Abysmal Brute 

"The Abysmal Brute" is a novel by American writer Jack London, first published in book form in 1913. It is a short novel, and could be regarded as a novelette. In the story, a successful boxer, who was brought up in a log cabin and knows little of the real world, begins to realize the corrupt practices in the game of boxing. (Goodreads)