Just need to point out that one of the other reviewers here has made a mistake. He's clearly thinking of "Challenge of the Ninja" (http://www.imdb.com/title/tt0080172/ ) not "Challenge of the Masters".
"Ninja" is the one with Gordon Liu (Liu Chia- Hui) marrying the Japanese girl and having to fight her relatives to prove whether Chinese or Japanese Martial Arts are best. It's especially memorable for the superb Chinese Sword vs Katana battle, still one of the great duels of Hong Kong movies, 25 years on.
Not as polished as later films by Chia-Liang Liu, "Challenge of the Masters" is still a pretty slick accomplishment when gauged against other contemporary Hong Kong films. Though shot in 1976, the movie looks as though it were made 5-10 years later. There's no doubt that the young Chia Hui Liu (Gordon Liu) is a star in the making. As always, his physical presence is arresting, his technical skills second-to-none and, heck, he's just plain likable.
His mentor Chia-Liang Liu does a reasonable job with the direction, but it's the fight choreography that shines here. His one-on-one fight with his protégé Chia Hui Liu in the bamboo forest at the three-quarter point is just excellent, and the interesting theme of martial arts binding its exponents together in brotherhood, is a refreshing change from all the revenge dramas that were coming out of Hong Kong (mostly from Chang Cheh, it would seem) at the time.