Great Movie around 1981, but Need Name

Hope someone can help me with this film title. I saw the movie around the 1980-1982 time frame (possibly 1979-1983), and although it's not the greatest kung fu movie, it made a lasting impression and I've been searching for years. In the finale, the hero and villain step on each other's feet during combat to stay afloat. The hero discovers a manual after the finale, which contains poison. The hero is about to open the manual, but a woman warns him about the poison; however, she dies due to injury during the final battle that will kill her if she speaks. Thanks!