Williams started his playing career in the Auckland Rugby League competition where he played with the Mt Albert club. During this time he gained selection for New Zealand and in a test against Australia was on the receiving end of a famous hit from Australian skipper Wally Lewis. This tackle was later described by commentator Ray Warren as easily the biggest he's ever seen. Williams later moved to Australia to play in the NSWRL premiership for the Manly-Warringah Sea Eagles. He played in the centres for the Sea Eagles' in the 1987 premiership final, and in doing so became the first Kiwi to play in an Australian grand final-winning team. Following the grand final victory he travelled with Manly to England for the 1987 World Club Challenge against their champions, Wigan. After several seasons with the club he was dropped in 1993, joining the Parramatta Eels for one more season in 1994.