Nan bei zui quan (1979)

A year after training young Jackie Chan in the Drunken Fist, Sam the Seed discovers he has a son, Foggy. He tries to train Foggy but to no avail. Foggy is then trained in Drunken Fist from his uncle as he must face his father's rival, Rubber Legs, another Drunken Fist master who combines it with Mantis Fist to create a deadly style.