In 2001, American Samoa’s attempts to qualify for the Fifa World Cup ended in a 31-0 thrashing at the hands of Australia – the worst defeat ever recorded in international soccer, a defeat that rewrote the rulebook. The one-sidedness of the encounter ensured the Oceanic zone had a preliminary qualifying round in time for the 2006 World Cup. It also contributed to Australia’s parachute drop into the Asian Football Confederation.

Twelve years after that record-breaking international, American Samoa continued to languish at the very bottom of the Fifa rankings, having scored only twice in 17 years. They needed a miracle.

Enter Thomas Rongen, a gruff Dutch coach who began his footballing career at Ajax before moving to the North American Soccer League, where he coached George Best and Johan Cruyff, before leading the U-20 US side to two successive world cups.

“I wanted to challenge myself,” Rongen tells me. “I didn’t want to think about potential failure. If you’re driven at the highest level, you want the biggest challenges.”

But how would the softly spoken, oh-so-polite islanders cope with Rongen's old-school hairdryer effect? This thrilling culture clash lies at the heart of Next Goal Wins, a heart-warming new sports documentary from British film-makers Mike Brett and Steve Jamison.

The directors were already filming the World’s Worst Team when Rongen took the post; he was the only applicant for the job. Was he disturbed to suddenly become the star of sporting underdog film?

“In my line of work – especially working in the United States – it’s very common to have that kind of media access in place. And I very quickly realised it was potentially a beautiful story. But I never thought I’d be attending the Los Angeles premiere. I never thought I’d be sitting here in London with Jaiyah talking to you.”

Jaiyah is Jaiyah Saelua, American Samoa's talismanic centre back: picture Roy Keane if he ran like a girl. An impossibly statuesque being, she's hardly big news in American Samoa, which has long played home to the fa'afafine (or those who live "the way of the woman"). But under Rongen, she entered the record books as the world's first transsexual international footballer.

They can laugh about it now. And do. But it wasn’t easy: at first Rongen thought she was the team masseuse. And Saelua’s initial impression of the coach was not entirely positive either.

“I thought he was very loud and cocky,” she laughs. “After the first session we all said something to each other about how obnoxious the coach is. But right away we could see that he loves what he does. So I knew he’d help the team with our development. I knew he was good for us. I saw it as an opportunity.”

Between tournaments, Jaiyah – or Johnny to her teammates – lives as a woman and studies dance and performing arts in Hawaii. Football must require an entirely different set of muscles, surely?

“It’s not so much a physical thing,” she tells me. “The discipline in dance and in soccer are very similar. But I do have to adjust my train of thought a little. I have to think tough. Dancing is soft. In football I think like a boy.”

Jaiyah’s inclusion in Rongen’s starting 11 is no gimmick. She and the World’s Worst Team do, indeed, improve over the course of the film.

“My biggest responsibility was to turn that losers’ mentality into a winners’ mentality,” says Rongen. “I had to make sure we got that first victory.”

In this robust spirit, he quickly introduced the islanders to such non-niceties as slide tackle. He found an extra man under the "grandfather rule". He recalled Nicky Salapu, the goalie who watched 31 go by two campaigns earlier. And he incorporated a traditional Samoan warrior chant – not unlike New Zealand's haka – into training.

“It was important to bring in that American Samoan warrior spirit. Show me how to fight and I’ll show you how to win.”

While Rongen toughened up his American Samoan squad, they softened his harder edges. Next Goal Wins chronicles a kind of spiritual journey for the troubleshooting coach, who took the job as a way of overcoming the loss of his 18-year-old daughter in a car crash. It was an incredible journey, he says.

“Beautiful island. Beautiful people. Great culture. A great culture of inclusiveness. Everybody goes to church. But in that spirit of inclusivity. There’s no judgment. There are no prejudices about gender or sexuality. The islanders have a refreshing, original way of seeing life. I’m so happy we can share that with people through the life. Because the first thing you think about the place is ‘I want to share this with everyone’.”

Both Jaiyah Saelua and Thomas Rongen are hoping for another crack at representing the nation of American Samoa: “I would love to,” says Rongen. “There’s still great untapped talent there. The 2018 World Cup in Russia: that’s our goal. That would be the perfect end to a perfect story.”

Until then, Jaiyah is still waiting for a major designer to answer her onscreen plea for red- carpet friendly frocks.

“I’ve had to buy my own,” she says. “Maybe it’s because I look terrible in the film.”

She really doesn’t.