What is the ruling of boxing as a career? Can someone reward a successful Muslim boxer?

Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Islam has made lawful all that is good and profitable and has forbidden all that is bad and corrupt.
The rule concerning sport and games differs according to the sport or game itself and to the objective for performing that sport or playing that game. So, any good and profitable game, according to Shariah, and which does not cause neglect of any Islamic duty and does not cause any physical or material harm to the person and does not itself contain anything forbidden, like exposing one's Awrah, any such game is lawful to be learned and practised provided it is performed without exaggeration.
But any game that does not comply to these rules is unlawful.
As for boxing, according to those who perform it, it is a game that does not bring any benefit to the person and it can cause much harm and many health problems to those who perform it. It can even cause death. There is no difference in this rule between free boxing and Olympic boxing. So, it is unlawful to perform it or take it as a profession or get some benefit from it or give financial support to those who perform it.
Allah knows best.