 In 1966, Green became the third person to pass a grading in the UK for a black belt in Shotokan karate, following Red Triangle clubmates Andy Sherry and Joseph Chialton.Green, alongside Sherry and Eddie Whitcher were also the first to be graded 2nd Dan in the United Kingdom, gaining their grade in 1967 at Crystal Palace.In 1967 Green won the inaugural KUGB kumite championships.