Plot

After being defeated by Ip Man,[a] Cheung Tin-chi lives a depressed life moonlighting as a mercenary before choosing to leave behind martial arts altogether and instead open a grocery store on the ground floor of his house. While on a delivery run, he runs into an opium addict named Nana and her friend Julia who are both fleeing from drug dealer Tso Sai Kit. Tin-chi ends up fighting with Kit's gang and defeats them single-handedly.

The Royal Hong Kong Police Force arrive and arrest everyone. Kit and his gang are released after bribing a corrupt senior police officer, while Nana and Julia are released by name-dropping Julia's brother, Fu, the owner of Gold Bar, one of the most popular bars on Bar Street. Tin-chi is eventually released late at night and is unable to take his son to a steakhouse called Petrus for his birthday.

Following the incident, Kit decides to seek out Tin-chi, with his whole gang setting fire to Tin-chi's building. Tin-chi barely escapes with his son Fung while being pursued by the gang and Sadi, a hired assassin. He is offered shelter at Fu's home by Julia, and works as a waiter at Gold Bar to pay his rent.

Angered by the injuries to his son, Tin-chi retaliates and sets Kit's opium den on fire. Kit's older sister, Tso Ngan Kwan, the head of a family crime syndicate wishing to transition to legal businesses, prevents Kit from taking revenge and visits Tin-chi at Gold Bar to compensate him for all damages Kit caused and for Tin-chi to drop the matter. Tin-chi refuses the money, impressing Kwan. At the same time, Tin-chi forges an increasingly close friendship with Fu over their shared pasts in martial arts.

Kit, attempting to escape from the shadow of his sister, decides to move into heroin dealing. He peddles his drugs on Bar Street for Owen Davidson, the owner of Petrus, who uses the restaurant as a front for his drug business. Tin-chi tips off Kwan about the business, who requests more time to settle the matter with Kit.

After finding Nana in a back alley, Kit and his gang kill her by forcing her to overdose on heroin. Tin-chi and Fu fight their way to the syndicate's headquarters, where they fight with Kit and Kwan. Kwan, attempting to placate them, cuts off Kit's right arm and forces him to reveal where he stores his heroin. Fu exposes the drugs to the media which makes newspaper headlines.

Soon after, Davidson has corrupt police officers plant drugs at Gold Bar and arrest Fu on drug charges. After arresting him, the senior police officer hands Fu over to Davidson to be killed in an unfair fight. Following the discovery that Davidson murdered Fu, Tin-chi fights with Davidson at his restaurant, during which he regains his confidence in using Wing Chun for good.

The senior police officer arrives to arrest Tin-chi despite Tin-chi's testimony that the heroin belongs to Davidson. Instead of complying, Sergeant Fai arrests his superior for corruption, assault and lets Tin-chi go free. Davidson attempts to escape in the ensuing chaos, but is assassinated by Sadi, who had been hired by Kwan before leaving Hong Kong with Kit.

Tin-chi returns to Julia's apartment and reunites with his son. The three of them share a meal together. In a mid-credits scene, Fung uses Wing Chun to defeat the boy who bullied him earlier.

Cast

• Max Zhang as Cheung Tin-chi, a former Wing Chun master who was defeated by Ip Man in a duel behind closed doors and subsequently becomes a mercenary
• Dave Bautista as Owen Davidson, the owner of Petrus and leader of a drug smuggling syndicate
• Michelle Yeoh as Tso Ngan Kwan, the leader of the Cheung Lok organized crime syndicate who wants to turn the gang into a legitimate business entity
• Tony Jaa as Sadi the Warrior
• Liu Yan as Julia
• Xing Yu as Fu, Julia's brother and former martial artist, who now owns Gold Bar on Bar Street
• Kevin Cheng as Tso Sai Kit, younger brother of Tso Ngan Kwan. He initially runs an opium den but becomes a heroin dealer behind his sister's back on Bar Street
• Chrissie Chau as Nana, an opium addict and Julia's close friend
• Patrick Tam as Ma King-sang, a former Triad leader and martial arts disciple
• Brian Thomas Burrell as a Inspector of Royal Hong Kong police
• Philip Keung as Fai, a sergeant of Royal Hong Kong police
• Adam Pak as Wang Yung, a constable of Royal Hong Kong police