One of the values that differs most between the sport of the past and the sport of our own era is the value placed on human life. The days of first-aid free Formula One races or bare-headed batsman have gone, although we can still relate to their logic and romance. Harder to understand is the decision to hold an invitational football tournament in the middle of a warzone. A delusional propaganda exercise, even in name – the Friendly Nations Tournament – was a bad idea. But from Botany Bay to Gallipoli, Australian history is built on bad ideas, and so it was with the country's football. The birthplace of the Socceroos success wasn't Sydney, it was Saigon, where the team won their first international tournament under flare-lit skies rumbling with helicopters with the Vietnam War in full flow.

Before this unlikely proving ground Australia's footballers had toured unhappily, banned by Fifa until 1963, then withering against North Korea in Cambodia in 1965, the first of many World Cup qualification snafus. The squad had been hot, sick, and underprepared for a technical North Korean team. Only two players continued on to Saigon in 1967, but one of them was 24-year-old captain Johnny Warren, and he was determined not to be humiliated again. The team was made up of people with day jobs – tailors, council workers, meat men. But it prepped hard, and the coach "Uncle Joe" Vlasits arranged for the ground to be inspected. But for a team so young it could have been sent to Vietnam as draftees instead, there were things that couldn't be trained for.

"It was going into the unknown," says striker and hall of fame inductee Ray Baartz. He was only 20 then. "We really didn't know what to expect – we knew there was a war going on there, but it never did at any stage feel that we were going into a warzone or anything like that. But once we got there, it was a real eye-opener."

Not only was the city crawling with military, with fighting close enough to hear the mortar pops, but all the international teams were a target for the Viet Cong, who made an abortive attempt to blow up the team hotel. Given its condition, a bomb attack might have been an improvement.

"The place was called the Golden Building," recalls striker Atti Abonyi, the tournament's most prolific scorer. "We all thought 'oh gee that sounds good' but … [the hotel] was absolutely atrocious – it was filthy, it was run-down. Nowadays nobody in their right mind would even stay there for two minutes. But because we were so excited, we put up with it regardless."

The food was rancid spam; the rooms even less appealing. Former Manchester United youth player Stan Ackerley went to switch on his fan, touched a live wire, and was shocked across the room, the burn going straight through his sock. And then there was the "training ground".

"There were no training facilities," says Abonyi. "They took us down to this little park – just a local park. It was terrible."

"The goalpost wasn't a proper goalpost. Somebody just made it up. And behind the goals there was a six- or seven-foot fence. We were having shooting practice, and a couple of the balls went over. And someone – I forget who it was now – was about to go retrieve the balls. And as he was half-way up, people were coming from everywhere screaming: "Don't go, don't go! No, no, no, no!" And we found out that the field behind us, where the balls had landed was full of bloody landmines. So the balls stayed. They could still be there now." Match prep was confined to gymnastics on the roof of the Golden Building.

Avoiding the local food so as not to get sick, the team began eating with Australian soldiers, who would become a small, vocal supporter base, eager to latch on to a winning cause for a change. "These were hardened young soldiers – and I mean young soldiers – they had seen more than we could ever dream of in a lifetime," says Ackereley. "But they made us very welcome. They took care of us. They said they didn't know much about it in them days – they were mainly rugby league supporters – but we invited them to come to the games, and they did."

The soldiers watched the game against New Zealand, where the field had to be swept for mines first, and the rain had turned it into a slurry of mud. Frank Milic struggled in the mire, was subbed off, and would never regain his spot. Abonyi scored a hat-trick, the first of two for the tournament.

"Even though Atti scored a lot of goals it was a real team effort," says Baartz. "Everybody worked their butts off, gave 110% effort. Conditions were atrocious, but the standard of football that was played was really good. We had penetration on the wings – Billy Vojtek on the right, Tommy McColl, on the left, so there was a lot of skill there. It was just a real all-round, exceptionally good team effort, with a lot of camaraderie, all for each other."

The game against South Vietnam was tense, heavy gambling adding to the tension in the crowd. Many of the Australian players were performing in front of crowds of 30,000 for the first time, but the difficult conditions were building the kernel of a team spirit that would define the decades to come.

The South Vietnamese vice-president visited the home side in the changing rooms at half-time, offering them six months' salary as a bonus if they could win. But Johnny Warren's goal was enough. He described it in his memoir Sheilas, Wogs and Poofters: "I don't vividly recollect scoring the winning goal but I remember the dead silence that greeted my goal. There was a full stadium but no noise! I had to look to the referee just to check the goal hadn't been disallowed." The goal remained, and so for the time being did the Australians.

"They told us at first not to leave the dressing room, and we stayed there for a good half an hour. It was obvious there was going to be trouble outside. So we thought 'let's wait until things sort of calm down a bit,'" says Abonyi. "And as soon as we were back on the bus there were rocks flying everywhere. Coming through the window, banging on the bus. Some hooligans, I don't know who they were. Pretty obvious they were young Vietnamese soccer fanatics going beserk. Unfortunately that happens all around the world. But it was pretty frightening at the time. This was meant to be the friendly game! It wasn't very friendly, I can tell you."

Against Malaysia, brawls broke out in the crowd, and the game was finished in a haze of teargas. But Australia were winning and reached the final. That was to be against South Korea, strong favourites with a sense of superiority about them. But the Australians were playing for more than just a trophy. "John Barclay, he was the team manager," says Ackerley. "Before the tour, he told us 'we want the tracksuits back'. And before the final, he said 'I'm going to take this on my head. You win the final, you get to keep the tracksuit.' So the big reward for going up to Vietnam in a warzone and winning the tournament, was actually that they let us keep our tracksuits."

The stadium was filled to capacity, and at first the team was told there was no room for the Australian soldiers who had cheered their progress. Threats were made to boycott the match and, miraculously, empty seats were found on the sideline. The Australians, a little nervous, took the pitch, and to their amazement were greeted by the South Vietnamese fans with enthusiastic cheering. They had forgiven South Vietnam's defeat, responding to the Australians' direct style of play and efforts to mingle in the city (the other teams had spent most of their time in the hotel). The South Koreans were booed.

"They didn't like the Koreans, for some reason, the Vietnamese," says Baartz. "They … sided with our team, whether it was the way we played football, or what it was I don't know. But we had more crowd support than they did. They turned it all around. It was nice, because we'd gone in as so-called underdogs, but to have people come out and start cheering for us – it was quite funny."

The Australian contingent hardly had time to absorb the surprise support, falling 1-0 behind in only the first minute to an opportunistic South Korean goal in what was to be a gruelling game.

"It was really hot and very heavy going," says Baartz. "It was just a mud-laden ground. So when you're playing in that heat and humidity, and the ground's such heavy going, and you haven't had a great diet, it obviously takes its toll on you. It was a good game, a hard game."

Australia fell back on team spirit. Abonyi remembers it "buzzing. It was impossible to describe." In the mud and heat, they somehow rallied to equalise, then scored two more goals for victory against a team that had been "crushing" all other opponents. After the failure against Cambodia, Australia had achieved the improbable.

"It was a tremendous result to win," says Baartz. "That tournament was just the first success of any Australian team anywhere … so it was a great feeling."

Whether or not the name "Socceroos" was first coined on the tour is still debated, but there's no debate about the team spirit.

"That tour established – a lot of people have coined the phrase 'The Pioneers' for that team – but the tradition and the camaraderie and the team spirit that has been instilled in the Socceroo teams over the years … a lot of the foundation of it was laid in that tour," says Baartz. "There was a tremendous amount of team spirit, a lot of singing and laughing and joking … everybody just got on so well."

They would play 10 games on the tour, including a dusty post-celebrations match against troops stationed down south. All would be won, with Abonyi scoring 13 goals.

"People say to me now sometimes, are you jealous?" says Ackerley. "Seeing the players now with their business class flights and everything. But I wouldn't change anything – we started it all. Even though people made a loss going on tour – we had to leave our jobs – this team made it possible for everyone else. And I've still got the tracksuit."