But one of the game’s most famous players still has one big regret when he looks back at his illustrious playing career.
In 1973, a star-studded Wales outfit competed in the first International Seven-a-side Tournament to celebrate the centenary of the Scottish Rugby Union.
It was the first rugby sevens competition to feature national representative teams and predated the first Rugby World Cup Sevens – the latest of which takes place in San Francisco this weekend – by more than 20 years. In their search for glory, Wales went for broke.
The legends of the 1970s – who remain household names in Welsh rugby to this day – were all there with Phil Bennett, Gareth Edwards, John Taylor, JPR Williams and Mervyn Davies joining JJ Williams in the side.
Remarkably, all that talent wasn’t enough to win the title as despite thrashing France 36-4 and a President’s VII 30-10, Wales were beaten in the semi-finals by an inexperienced England team.
“We should have won that competition and it still bugs me,” said JJ Williams. “The reason we didn’t win is because in the semi-final we picked Mervyn, JPR and John as our front-row. We couldn’t get any ball and England had specialists in the front-row including Fran Cotton.
“We had this amazing back-line, but we didn’t touch the ball in that game.
“I had only just won my first senior cap against France a couple of months before the competition. We were the favourites because we had so many of the Lions from the famous 1971 tour.
“England’s side were mainly made up of men from Loughborough University, although they did have some good players like Fran and David Duckham.
“Even so we were much better than them. In all fairness we played some brilliant rugby throughout the campaign, but we should have beaten England.
“They denied us possession and won the game.”
Williams and his superstar team-mates could have been forgiven for treating the competition as an afterthought following their Grand Slam and Triple Crown heroics.
But for the men involved, the prestige of playing was never in doubt.
“Sevens was very big with some of the best players in the world at the time playing,” Williams added. “Obviously you had all the Welsh boys, but in Scotland there were guys like Andy Irvine, Fran, David, Mike Gibson and Fergus Slattery. It was a bit like a mini Five Nations with a big crowd.
“It was a novelty event because it was so international. Scotland were good in those days because sevens was started in Scotland and they were very good technically.
“Back in those days sevens was huge in the UK, but not so big globally and the best sides were British.”
This year, senior Wales 15-a-side internationals Justin Tipuric, James Davies, Cory Allen and Hallam Amos have all represented their country in sevens, while Allen and Cardiff Blues scrum-half Lloyd Williams are both in action in the USA this weekend.
Lions great Williams laments the fact sevens isn’t as celebrated in Wales as it once was. He has called on some of Wales’ star 15-a-side players to be selected for the international sevens events moving forwards.
Williams said: “Sevens was very popular in my day. You had the Gala Sevens in Scotland and when the Snelling Sevens was on in Cardiff, you had 50,000 people watching.
“All the clubs in Wales played there and I won it a few times with Bridgend and Llanelli.
“The thing is these days you have players who are considered sevens specialists, but back in the 1970’s we were all sevens specialists in Wales because we played in a lot of sevens competitions.
“I really think we are missing a trick by not picking our best players to play sevens for Wales.
Playing the abbreviated form of the game aids player creativity, said Williams, and “sending players away to play sevens could really benefit their skill levels and spatial awareness.”
Wales begin their Rugby World Cup Sevens campaign this Friday against Zimbabwe at 22:07 BST.S4C will be showing highlights of the Rugby World Cup Sevens this Saturday (19:30), Sunday (19:30) and Monday (18:30).?
Wales Sevens: Luke Treharne, Ethan Davies, Lloyd Williams, Luke Morgan, Owen Jenkins, Tom Williams, Cory Allen, Afon Bagshaw, Adam Thomas, Cai Devine, Jared Rosser, Ben Roach. Travelling Reserve: Will Talbot-Davies.
Visit the RWC7s website here.