It was a month like no other in the history of New Zealand league, featuring a series of feats which will almost certainly never be repeated.
In the space of three weeks back in June 1977 the Auckland representative side, made up of part-time players ranging from meat workers to the local police officer, conspired to down the might of Australia, Great Britain and France in mid-week matches.
This week for the first time in 40 years, all 19 of the players from that team who completed the 'grand slam' will get together to celebrate the achievement, and will be guests of honour at Friday night's NRL Telstra Premiership match between the Warriors and Canterbury-Bankstown Bulldogs at Mount Smart Stadium.
"There's 19 of us in the team photo, we thought we better get together before we all start dropping off," joked Fred Ah Kuoi, a utility back in the Auckland side who later played first-grade for the North Sydney Bears.
"It has been a lot of fun recently thinking back to that year. It was an exciting time for us, but it's just now that we look back and I think 'gosh, we did something quite special there', it's taken that time away to realise it fully.
"I was asked the other day whether we celebrated at the time, I thought about it and yeah we did and we were all happy and joyful, but we had to go to work the next day. It was a mid-week game and obviously you couldn't fully savour it, you had a shower, went home and got up for work the next day."
After edging past Australia 19-15, Auckland then beat Great Britain 14-10 a fortnight later and finished with a 17-0 shutout of France, who at the time were a dominant force on the international stage.
Among the 19 who took the field for Auckland in those matches was future New Zealand Player of the Century Mark Graham, who in 1981-82 won consecutive Dally M Second-Rower of the Year awards while with North Sydney, along with names such as Olsen Filipaina and Kurt Sorensen who would later enjoy lengthy stints with Sydney clubs.
Stan Napa, father of current Sydney Roosters and Queensland Maroons enforcer Dylan, was also in the team.
While the professional game in 2017 resembles little of what the 1977 side played through, former Auckland and Kiwis prop Lyndsay Proctor said the players of that time feel immense pride in seeing the Warriors now playing in the NRL.
"Looking at the Warriors now and what they are all about, that was always a goal and dream of George Rainey (the Auckland Rugby League chairman in 1977)," Proctor said.
"To see them playing week in, week out in the Australian competition, and giving local kids the chance to stay in their own country and play against the best, that's great because that was something we always wanted.
"It all started from things like the 1977 season when we were able to prove the quality we had here in New Zealand. Whatever role we played in driving that push for the Warriors, we are proud of that."