Career
Fenwick played rugby as a schoolboy for Caerphilly Grammar Technical School, and later joined Taffs Well Reconstruction Finance Corporation. In 1971 he switched to Beddau where he played 51 games before moving on the first class team Bridgend. While at Bridgend Fenwick earned all of his 30 international caps for Wales, making his debut against France in 1975, in which he scored a try after only five minutes, and finished the game with a personal tally of 9 points. He also captained Wales in the Centenary game against the All Blacks in 1980.
He also played for a World XV on 9 August 1980 against Argentina in Buenos Aires, losing 36-22.
In August 1981 Fenwick switched from rugby union to professional rugby league, signing to the Cardiff City Blue Dragons. He made his debut for Cardiff against Salford scoring four goals in the match.
Before the start of the 1984/85 season, Cardiff City Blue Dragons relocated from Ninian Park in Cardiff, to Coychurch Road Ground in Bridgend, and were renamed Bridgend Blue Dragons.