At the age of 11, he began participating in challenge matches on the school playground, practicing Tai Chi Chuan, which was insufficient to distinguish him among Hong Kong's youth.

[7] Around 1954,[10] a turning point in Cheung's life came when he witnessed a gang leader, undefeated in combat, challenge an elderly man who was rumored to practice a lesser-known Kung Fu style created by a woman.

[11] Initially, Ip Man rejected Bruce's request to learn Wing Chun Kung Fu due to a longstanding rule in the Chinese martial arts community that forbade teaching foreigners; Lee’s one-quarter German heritage from his mother's side presented an obstacle.

After graduating in 1969 with a bachelor’s degree in economics, Cheung fully immersed himself in Wing Chun theory and practice, working closely with a group of dedicated students.

[citation needed] In 1973, Cheung founded a martial arts school in Melbourne, Australia, and in 1976, he was elected president of the Australian Kung Fu Federation.

In September 1986, William Cheung was attacked by 24-year-old Emin Boztepe, a Wing Chun practitioner from the EWTO, while conducting a seminar in Cologne, West Germany.

[16] The federation began organizing the Australasian Kung Fu Championships around 1977–1978, which were among the earliest full-contact tournaments in Australia open to all styles of martial arts.

[20] Cheung was recognized as one of Ip Man’s disciples who helped establish Wing Chun's reputation as a fighting art through the challenge matches in Hong Kong.