The Kiwis team was bereft of experience, with Mark Graham (retired), Kurt Sorensen (unavailable), Dane Sorensen (injured) and Kevin Tamati (unavailable) all out of the reckoning.
Two-thirds of the 15 man test team were domestic-based players, with only Hugh McGahan, Clayton Friend and Darrell Williams based in the Winfeld Cup, while Dean Bell and Mark Elia returned from the Northern Hemisphere.
It was a team full of 'local heroes', some of whom were earning as little as $25 a week: unknown Bay of Plenty winger Gary Mercer, rugged Canterbury prop Ross Taylor, Auckland second rower Mark Horo and a 19-year-old Kevin Iro, plucked from the Auckland Fox Memorial competition.
In contrast, the Kangaroos were full of superstars. They had strolled unbeaten through a tour of Britain and France the previous year, recognised as an even better outfit than the 1982 Invincibles.
The backline was marshalled by Wally Lewis and Peter Sterling, with Brett Kenny, Michael O'Connor and Gene Miles outside them.
The pack included hard men Peter Tunks and Greg Dowling, alongside athletic back rowers Wayne Pearce and Bob Lindner.
"They had so many great players," said Bell. "Even I was a bit in awe of that team. But I knew we would rise to the challenge."
The Kiwis, coached by newcomer Tony Gordon, who had replaced Graham Lowe, beat Riverina and Queensland (featuring Lewis and five other Origin representatives) before a tough test win in Papua New Guinea.
"It was great for bonding," said Friend. "We had a few good sessions because you couldn't really leave the hotel."
They arrived back in Australia on the eve of the third State of Origin.
"We couldn't get any tickets so we watched it in the hotel," said Friend. "It was daunting, but also quite enjoyable, watching them bashing the hell out of each other."
Preparation started in earnest the next day. As he had emphasised all tour, Gordon demanded a strong physical base.
"We were flogged," remembered Friend. "We did countless 400s - no one likes those. But it made us stronger and probably helped us get through what we were going to face."
Although they had been written off, belief and camaraderie was building in the New Zealand camp.
"There was a real togetherness - I could sense it when I arrived," said McGahan, who joined the team for the Australian test.
Senior players worked to instil confidence in their inexperienced team-mates but found it already present.
"When you are young, you don't really care about reputations or names," said Shane Cooper.
"A lot of us had only played one or two tests but we had nothing to be afraid of."
In the dressing room before the game, Gordon pulled a rabbit from the hat, playing a recording based on the wartime song Maori Battalion.
"The room fell silent and not a word was said," said Wallace. "I remember thinking, 'I think we're going to go all right'."
As recounted in The Kiwis, Australian coach Don Furner was having trouble motivating his team. Coming off an epic Origin series, it was hard to imagine the test against a largely unknown Kiwis squad would be little more than a training run. Their complacency was reinforced early in the match, when Sterling crossed for a try.
"That probably didn't help them," said Bell. "They thought it was going to be a stroll."
Instead the Kiwis settled into their work.
"We had a rugged pack and we tried to unsettle the Australians," said Cooper. "It worked and we grew in confidence."
The Kiwis also had some new moves, surprising the Kangaroos by regularly turning and pivoting just before the line to pass, then going wider. Iro and Bell made inroads in the backline, and the likes of Taylor and Horo belied their inexperience.
Stewart set up Taylor for the first Kiwis try, with the prop forward running 25m to dot down near the posts. More was to come, when a sweeping backline move was finished by Mercer, who produced an extravagant sidestep to beat the last defender.
Just before the break, Cooper hit a wobbly drop goal to give the Kiwis a 13-6 halftime lead. Momentum flowed back towards the Kangaroos in the second half. They completely dominated possession, with the Kiwis struggling to progress out of their own territory.
"It was relentless," said Bell. "They kept coming and coming. But we kept tackling."
The men in the black and white V repelled numerous assaults and with a few minutes on the clock, the Kiwis cleared the ball over the sideline, inside the Australian half.
"I'll never forget the smile on Clayton Friend's face," said McGahan. "He had a cheeky grin and said 'we've bloody done it'."
It was just the third Kiwis win over Australia since 1971, and the most unexpected.
"We sat in the changing rooms and everyone just looked at each other in disbelief," said Wallace.
Celebrations were prolonged. The team was joined by dozens of Kiwis supporters in the hotel before heading out into the Brisbane night.
"I spent most of the night in my room icing my shoulder," said McGahan. "I had an early flight back to Sydney the next morning and when I left, most of the boys were still out."
Australian dominance was re-established in the following years, but that night, a curious mix of greenhorns and veterans touched the void.
"We were a team as one," said Friend. "We were so united. In the big games, that makes all the difference.
"It was a special group," said Wallace. "Even now, if I see any of the boys, I'll give them a hug. It's been 30 years but nothing has changed."
