Fist and Fang

A boxer has left the ring and is sailing the South Seas. He and a friend have run off to visit a native friend, and find out the old chief has been killed, and his replacement is the boxer's old enemy.
There is a graphic, extended, bare-knuckle boxing match.
It's not Joseph Conrad or even Jack London, so it doesn't have quite the atmosphere of someone who had actually visited the place, but it's tight and well-crafted.