Undisputed 2: Last Man Standing (2006)

Heavyweight Champ George 'Iceman' Chambers forced to fight for his life in the brutal world of Russian prison boxing. Imprisoned in Russia and forced to rely on his street-fighting skills as a means of surviving, Chambers soon discovers that in the unforgiving Russian penitentiary it's one's willingness to break the rules - not play by them - that could mean the difference between life and death.