Ex-gang member John Henry is a quiet man with a violent past. When two immigrant kids on the run from his former South Los Angeles gang leader stumble into his life, John is forced to reconcile with his past in order to try and give them a future.

Years after a childhood prank goes horribly wrong, a clique of South Central LA teens find themselves terrorized during Homecoming weekend by a killer hell-bent on revenge.

1964年，年轻的阿里（Will Smith 威尔• 史密斯 饰）凭着高超的拳术，坚韧的毅力战胜尼桑•里斯顿成为了新的拳王！时值越南战争期间，阿里拒绝服兵役，因为“越共没有管我叫黑鬼”。正因为阿里直率的性格，拒绝向自己认为错误的事屈服，阿里因此吃尽苦头：美国政府用尽方法企图将阿里投进监狱；拳击理事会剥夺了阿里拳王的金腰带。在1964至1974这社会动荡的10年里，阿里表现出的坚忍不拔的毅力和决不屈服的独立性不仅对他个人，对拳击界甚至对整个社会都产生了巨大的回响，阿里亦因此成为黑人运动和反越战运动的精神领袖。 1974年，阿里出乎所有人的意料，以34岁的运动高龄，再次参加拳王争霸赛。