Iron man (1973)

During the Japanese occupation, Little Tiger, an honest cook in Shanghai, takes exception of two Chinese that pass from insult to sexual harassment against a beautiful and modest girl servant. During the fight, the pair of molesters receive help from a number of colleagues from the same martial arts school - who are in support of the Japanese - while Little Tiger is helped by young men from his own school. A major fight develops, and the cook accidentally kills one of the thugs. The Police comes to arrest Little Tiger and to close down his school, but they resist and the cook escapes. Little Tiger is now a fugitive, living in disguise. When a duel between the two rival schools is arranged in an open-air site, Little Tiger is watching disguised as an old man, but he can't resist. He takes off his false beard, declares his name, and demands to join in the competition - beating up all competitors.