The first Hong Kong Sevens took place in front of a few thousand curious spectators, and some of the players wore gym shoes in the mud instead of rugby boots.
Fast forward 50 years and the event has grown into a sold-out three-day festival of global repute, mixing sport with socialising, schmoozing and big business.
The runaway success of the Hong Kong Sevens played a key part in rugby returning to the Olympics at Rio 2016 after a 92-year absence.
France's thrilling men's sevens gold, inspired by home hero Antoine Dupont, was one of the standout moments of the Paris Games two years ago.
The Hong Kong extravaganza – where legends such as Jonah Lomu and David Campese played in the past – also had a central role in developing the rugby across Asia.
Speaking to AFP on Friday as Hong Kong's biggest party kicked off, World Rugby chair Brett Robinson said there was nothing quite like it.
"It's the pinnacle," he said.
"Firstly, it's sort of one of the pinnacle events in global sports, let alone rugby.
"It's the jewel in the crown of our Sevens series."
'REALLY SPECIAL'
Packed crowds with many flying in from overseas for the weekend are a far cry from when a group of club enthusiasts launched the event in 1976.
Now there are men's and women's sides from all over the globe, but then it was mostly teams from Asia and the Pacific in a one-day men's tournament.
"It started as a bit of a jolly," former Hong Kong Rugby Football Union president Brian Stevenson, who was involved at the start, once reflected.
A few of the Hong Kong players did not even have the proper footwear, and one of them was a policeman.
A 3 000 crowd packed Hong Kong Football Club to see New Zealand's Cantabrians win the first Hong Kong Sevens.
"It was a kaleidoscope of colour, full of the pace and grace, thrills and spills and the glorious uncertainty that make seven-a-side rugby arguably the fastest and best ball game in sport," local newspaper the South China Morning Post purred in its report at the time.
The seed was sown, and the tournament grew as a commercial and sporting success in tandem with Hong Kong's development as a global financial centre.
The 40 000-capacity Hong Kong Stadium became the tournament's home, with the South Stand in particular providing a raucous backdrop of well-oiled party-goers decked out in outrageous fancy dress.
After the Covid pandemic put a temporary spoiler on things, the tournament last year moved to the new $3.85 billion Kai Tak stadium.
The 50 000-seat arena, which boasts a futuristic purplish facade and retractable roof, is purpose-built for rugby sevens with 24 separate changing rooms.
It is on the site of the old Kai Tak airport, famed for its hair-raising approach over the top of nearby housing estates.
Robinson said that when rugby was applying to become an Olympic sport again, delegations were shown Hong Kong to help stake its case for inclusion.
"It's just really special in terms of the scale of it, the attendance rates, the momentum and the history of the tournament," he said.