Death Duel of the Mantis(1978)

Hsiao Hai (Ting Wa-Chung) is a kung-fu servant of the big boss (Lung Fei). Bullied and abused, he finds himself taken under the wing of the boss when he stops some troublemakers rising in status. Hsiao Hai begins to learn the boss's dreaded chicken fist and also falls in love with a girl, Shao Hua, who works at a food stall. Shao Hua and her father are mantis-fist experts and inform Hsiao that his boss is not the upstanding man he appears to be.