continued to grow in stature when within a year of signing for Dudley Kingswinford, Watson was selected for his first representative role with the Worcestershire and Herefordshire Combined Counties side and playing on several occasions in a new role of prop-forward. At the end of the 1959 season Watson decided on a switch of codes after wanting to forge a career in rugby league. After viewing an advertisement listed in the Sporting Chronicle by St. Helens offering trials for 'top class Rugby Union forwards', Watson replied offering his services to the club and outlining his statistics and credentials he had accomplished in rugby union. St. Helens quickly replied and a trial was organised for 2 August after which Watson was signed to a six-game contract worth £1,500. St. Helens He made his début for the Lancashire club on 15 August 1960 playing at prop-forward in what turned out to be a defeat by local rivals Liverpool City at home. However he quickly adjusted to the new game, slowly establishing himself and garnering a reputation as a tough, resilient and hard working player amongst fellow professionals and spectators alike something which never did never change throughout his career. Watson played out the six matches as per terms on his original contract and quickly re-signed for the club establishing himself further with each passing game played. After a mere eleven competitive matches for his new club Watson shot to fame in the 1961 Rugby League Challenge Cup Final against Wigan with his quick thinking and often vital defence; although it took Watson a further seven matches to garner his maiden first grade point against Barrow on 23 September 1961. After the Challenge Cup Final Watson became a regular first team member of the Saints side of the 1960s. Watson tasted further success in 1961 with a Charity Cup victory in 1961. His career continued to flourish for St. Helens during the rest of the 1960s being first selected for Great Britain in 1963 and winning the Western division Championship in 1963; the Gallie Cup in 1964, 1967, 1968, 1969 and 1970; the Championship trophy in 1966 and a further Challenge Cup in 1966. Watson played his 373rd and last match for St. Helens in England on 7 May 1971 against Leeds before being enticed to sign with newly formed Australian club the Cronulla-Sutherland Sharks by ex-teammate and present Sharks player-coach Tommy Bishop.