He was appointed as Welsh National Coach in 1957 and was also a finalist in the 2nd Dan European Championships of that year. He represented Wales in a three-cornered match against England and Scotland in 1953 and competed in the 1964 Olympic Games in Tokyo. In September 2010 Petherbridge was inducted to the Welsh Sports Hall of Fame.
Starting Judo at Swansea Judo Society at age of 22, he was captain of the team to win Matsui Challenge Cup 1955 and gained his shodan (1st Dan) the same year - the first Welshman to gain that grade. Petherbridge won the Goldberg Vass Memorial Trophy in 1956 and was a member of the British Team from 1956 to 1958. He achieved nidan (2nd Dan) in 1957.
