Lam Sai-wing, Sammo Hung Kam-Bo, also known as Butcher Wing, is a student of Wong Fei-hung. His long-lost brother Lam Sai-kwong arrives in town with his beautiful wife Yuet-mei, and trouble quickly follows when Ko Tai-hoi, the son of Master Ko Ba Tin, spots Yuet-mei and abducts her, driven by lust. The abduction is witnessed by Master Ko's goddaughter Lan-hsing.
Wong Fei-hung slips out of town, leaving Butcher Wing and the other disciples, including Leung Foon and Chat, to fend for themselves. Sai-kwong challenges Tai-hoi, threatening to murder him if he does not free Yuet-mei. Butcher Wing arrives and, not recognizing Sai-kwong, stops him and drives him away. A despondent Sai-kwong contemplates suicide, only to be saved by the wily drunkard Beggar So, an old friend of Wong Fei-hung with formidable kung fu. Sai-kwong explains his plight, and Beggar So confronts Tai-hoi, who claims that Butcher Wing abducted Yuet-mei. Beggar So presses for a meeting with this supposed brother, and through a clever introduction, Butcher Wing and Sai-kwong realize they share a connection. Together with Beggar So, they uncover that Tai-hoi still holds Yuet-mei.
Lan-hsing tries to rescue Yuet-mei but is captured by Tai-hoi, who also keeps her as a prisoner. Butcher Wing and Beggar So team up to free Yuet-mei from Tai-hoi's henchmen, and they manage to release Lan-hsing as well, though she keeps her true identity secret. They return to Butcher Wing's home, where Lan-hsing, feeling slighted by a blunt insult, decides to stay the night, feigning an injury that keeps her from walking. Beggar So, who has begun to drink again, drifts into a stupor, and the ruse is nearly exposed. Tai-hoi breaks into the house and attempts to rape Lan-hsing; she resists and screams, and in the struggle Tai-hoi accidentally kills her. A passing night watchman finds the scene and a ring left behind by Tai-hoi is recovered.
Tai-hoi accuses Butcher Wing of the murder, prompting Master Ko to march with two students to destroy Po Chi Lam’s sign, believing the rival school will shelter the accused. Leung Foon and Chat strike back at Master Ko and his followers, while Butcher Wing arrives amid the fray, and Master Ko fatally injures him. Beggar So ferries the dying Butcher Wing to safety, where he receives healing and frank critiques of his kung fu from the old master. Under Beggar So’s tutelage, Butcher Wing embarks on a grueling training path to sharpen his skills.
The night watchman, hoping to cash in on the situation, tries to extort Tai-hoi by selling back the ring. Tai-hoi murders the night watchman and Sai-kwong, and Yuet-mei escapes with the ring, bringing crucial information to Butcher Wing about Tai-hoi’s true crime. Later, Butcher Wing crashes a private party on a rented boat, carrying Sai-kwong’s funeral tablet as part of his plan for vengeance. He defeats Tai-hoi in combat, and Tai-hoi, cornered and desperate, is slain when Butcher Wing delivers the final blow with the funeral tablet.
Come morning, Master Ko mourns the loss of his son and orders Tai-hoi’s funeral to be held in the town square, waiting for Butcher Wing to appear. When Butcher Wing arrives, Master Ko attempts to murder him, but the two clash again, this time with Butcher Wing turning Tai-hoi’s funeral tablet against Master Ko. The fight intensifies, and with Beggar So’s help, Butcher Wing drives Master Ko to submission. Just as peace seems within reach, Wong Fei-hung returns to the scene, and the film closes with a light-hearted sting as the grandfatherly hero prepares to discipline Butcher Wing for allegedly misplacing Po Chi Lam’s sign—an act that ends up turned upside down, much to everyone’s amusement.
