The Thunderbolt Fist.

A small village is taken over by the nasty Japanese, who kill the town's top kung fu fighter in order to scare the populace into submission. Escaping the wrath of the Japanese, the son of the master flees into the hills, where he trains with a group of rebels led by Gam Kei-Chu. Fast-forward ten years, and Chuen returns to the village armed with his father's secret technique of the Thunderbolt Fist with the hopes of killing the leader of the Japanese.