In April 1960, he created a goal for Bill Atkinson in a 3–0 defeat of Wales Schools;[5] a few weeks later, the favour was returned in a 5–3 win against the Scottish Schools XI, when "England scored within 30 seconds of the start, the ball flowing sweetly from right to left, for Atkinson's centre to be summarily despatched into the net by Thwaites".
[6] He joined First Division club Birmingham City as a 15-year-old in 1960,[7] and made his first-team debut a year later, standing in for Bertie Auld in a League Cup loss to Swindon Town in September 1961.
[9][10][11] He turned professional in May 1962, and played in several First Division matches at the start of the 1962–63 season, displacing Auld from the side.
[17] The couple moved to Blackpool where they raised their daughter, Lindsey,[17] and where Thwaites worked as a hospital porter.
[2][18] While on holiday in Port el Kantaoui, Tunisia, in June 2015, Thwaites and his wife were among those murdered in the Sousse attacks.