Xiao lao hu (1973)

Young Tiger, a martial artist in modern-day Hong Kong, fights a braggart in a martial-arts studio and defeats him. He later witnesses the braggart getting beaten up by a gang of thugs. After entering the fight, he gets knocked out and his friend gets killed. The thugs frame him for the murder, and the police soon arrest him. Young Tiger escapes prison during interrogation, then decides to find and fight the thugs' gangster boss while evading police who are looking for him.