加州沙漠的甜水监狱，在一群疯狂的犯人观众之中，监狱拳王蒙罗•哈金（韦斯利•斯奈普斯 Wesley Snipes 饰）再一次击败了他的对手。哈金曾是一名拳手，因杀人被判终身监禁，他凭借出色的拳击技术，在监狱之间的拳击联赛中蝉联十年冠军。此时，重量级拳击冠军“冰人”乔治•钱伯斯（文•瑞姆斯 Ving Rhames 饰）因强奸罪被起诉，被收押在甜水监狱。监狱众人认为蒙罗和冰人之间必有一战，阅拳手无数的狱中拳赛安排者——雷顿开始筹划两人的比赛。冰人坚称自己并未犯罪，利用自己拳王的影响力在狱中向监狱长施压，同时不忘挑衅蒙罗这种他根本看不上眼的狱中拳手。蒙罗在和冰人的对峙中尽落下风，早早就被监狱方面关入了单人牢房，二人的决战，似乎已不可避免……George "Ice Man" Chambers (Rhames) is a top ranked heavyweight boxer. However Chambers has his world turned upside down when he is accused of rape and sent to prison. Upon his arrival he hears talk about Monroe Hutchen (Snipes) who is the top ranked prison boxing champ 10 years running. Immediately there is bad blood with Chambers not wanting to be second to no one which leads to a lunch room fight between the men. Figuring it will be a good way to make money fellow convict Emmanuel 'Mendy' Ripstein (Peter Falk) sets up a prison boxing match between the two men to decide who is the real UNDISPUTED champ. Michael Rooker plays a guard, Fisher Stevens, John Seda, and Master P co star.