Chen Zhen (Bruce Lee) returns to the Jing Wu School to attend the funeral of his teacher, Huo Yuanjia. Chen is beside himself and can’t believe that his beloved master would suddenly die from an apparent illness.

Later the Japanese arrive at a ceremony held for Master Huo and present the school with a sign reading the words “Sick man of Asia”. The sign’s intentions are to offend the chinese as being the weaker race. The interpreter for the Japanese, Mr Woo, attempts provoke Chen into a fight who struggles to remain calm.

Afterwards Chen pays a visit to the Japanese dojo to return the sign they gave them and ends up fighting them all. Proving that his skills are far superior to that of the Japanese.

Angered by this, the Japanese go to the Jing Wu school in retaliation. Beating up the students and taking down a picture of their teacher. They demand that they want Chen and leave them with two choices, either hand over Chen or be arrested and have their school closed down. The students all agree that Chen it would be best if Chen leaves Shanghai and make arrangements to help him escape.

That night, Chen secretly overhears a conversation between the school’s cook and the caretaker and discovers that his master did not die of Pneumonia but was murdered after consuming biscuits laced with poison. Blinded by rage, Chen unleashes his fists of fury and kills both men to avenge his teacher.

The next morning both men are found hanging. The Japanese quickly figure out that it was Chen who murdered them. The police search for him but he is nowhere to be found.

Seeking revenge on those responsible, Chen finds himself in a situation in which he cannot escape in a fight to defend the honour of the Chinese and to bring to justice those responsible for his master’s death.