In 1966 the tournament returned to Cardiff and such was its success that it was held there until 1982. As in 1964 David Watkins, Brian Price and Stuart Watkins were unavailable, this time due to the British Lions tour to New Zealand and so Newport had to field a shadow side but magnificently led by Bob Phillips they defied the odds and cruised past Aberavon and Ebbw Vale to reach the semi-final. Here they had a tremendous fight before overcoming Newbridge 10-8 to reach their 11th final and meet Cardiff in front of a 30,000 crowd.

Before they knew what hit them they were 15-5 down but incredibly they fought back to lead 20-15 only for Cardiff to score in the very last seconds and force the match into extra-time. Tony Williams then scored the winner for Cardiff. It was heart-breaking for the Newport fans but they had played their part in what was the greatest final to date.

Newport team : John Anthony, Gordon Britton, Bob Phillips, Cliff Williams and forwards John Jeffrey, Brian Perrins and Alun Thomas.

Aberavon 15-6 W
Ebbw Vale 10-3 W
Newbridge 10-8 L
Cardiff 20-23 L (after extra time)