Ng Sze-Kwang was the first local Chinese person to become a national singles champion in Hong Kong, winning six consecutive Hong Kong Lawn Tennis Championships from 1918 to 1923. He was also a three-time runner-up in 1915-16 and 1927. From 1917-19 and 1922-23, respectively, he also took five doubles titles with two different partners. In the doubles, Ng was also a four-time runner-up. He also represented China in the 1923 Far Eastern Games and in 1924 was a member of the first Chinese Davis Cup team. Ng served as chairman of the Hong Kong Chinese Sports Association.