Syed Abdul Kadir started his boxing career competing in championships when he was at St Andrew's Primary School. He soon progressed to a proper training regiment under boxer turned coach Lee Wee Kee when he was 18 and proved his skill by defeating bigger opponents in the light flyweight.

He then trained under the tutelage of K M Abdullah in 1968 and won the Singapore Open title the same year and keeping it for the next 8 years. His quick progress led him to the international stage where he represented Singapore at the 1969 SEAP games. His continued participation in the games over the decade yielded a gold and two silver medals.

He became Sportsman of the Year in 1974 for winning Singapore's first medal in boxing at the 1974 Commonwealth Games in New Zealand.