Matthewson became a Football League linesman in 1966 and two years later joined the list of referees. He made a quick impression and was senior linesman for the 1970 FA Cup Final between Chelsea and Leeds. A year later he took charge of a League Cup semi-final between Stoke City and West Ham United and in late 1972 was promoted to the FIFA List of referees. He was in charge of the remarkable 1974 FA Charity Shield match. This was Brian Clough's first major match as manager of Leeds but became better-known for a double sending-off. Matthewson sent Leeds United's Billy Bremner and Liverpool's Kevin Keegan off for fighting, the first time players had been dismissed in a major British club match at Wembley. The following year he was referee for the FA Cup semi-final at Hillsborough between Birmingham City and Fulham. His career in England culminated with Manchester United's 2–1 win over Liverpool in the 1977 FA Cup Final, the result ending Liverpool's hopes of the domestic League and Cup double. In May 1977 he signed on to become an official in the North American Soccer League.