The crowd swelled as the game went on. From scores to hundreds to a thousand or more, young and old, men and women, all gathered in front of the big screen in the square of Newtown Junction, in the very centre of Johannesburg.

No one spread the word that victory for the Springboks was possible, let alone imminent. No one needed to. By the middle of the second half, there were no more shoppers hunting for bargains. The gym in the mall was empty. The queues at KFC, the Indian takeaway and the grilled sausage stand had disappeared.

And, as unseasonable grey skies gave way to the usual brilliant blue and it became clear that victory was assured, the celebrations began. “I’m so proud. It’s our first win with a black captain,” said Sibusiso Radebe, 37, an insurance underwriter, referring to Siya Kolisi.

South African captain Siya Kolisi with his children after the end of the match. Photograph: Tom Jenkins/The Guardian

“It’s amazing,” shouted Kwenzi Vilakai, a 26-year-old fitness trainer, amid the whoops, yells and cheers. “Whatever we do, we have to be united and support each other. It makes me hopeful for my country.”

Her friend Cathy Shabalala, a 25-year-old student, danced. “As South Africans, this feels so great. We are not always like this. And the bonus is we have played against our old colonisers and we have beaten them! We have killed them!”

The crowd had been subdued when the Springboks took to the field and sang South Africa’s multilingual national anthem. There was even a brief moment when the chorus of Swing Low Sweet Chariot from England fans in the stadium in Yokohama was audible over speakers from almost 14,000km away.

As the South Africans’ strength on the field became clear though a new song rang out, drowning out all else and the crowd, arms aloft, began to sway.

Celebrations in Tygervalley, Cape Town. Photograph: STR/EPA

Shosholoza, a stirring call and response chant with rolling harmonies and haunting lyrics, once kept gold miners swinging their picks under the apartheid regime. But since the coming of democracy, it has become a much loved staple of sporting events, famously sung when the Springboks won the Rugby World Cup in 1995, a year after South Africa’s first free election. That victory, and the presentation of the trophy to Francois Pienaar by Nelson Mandela, helped heal a traumatised nation.

As the lines “Go forward, go forward” rang out around the square, Tsholoselfo Ranyane, 26, said she felt very patriotic, and that that was a good thing because “South Africans need to be more patriotic right now”.

For years, the 55 million citizens of the rainbow nation have had little to cheer. The country remains one of the most unequal in the world. There is deep public frustration with soaring joblessness, patchy delivery of basic services and widespread official corruption. Drought is causing severe water shortages. There are rolling power cuts. The centre of Johannesburg, the zone around the Newtown square, has a well-earned reputation for violent crime.

Fans in Cape town enjoy the match. Photograph: Mike Hutchings/Reuters

“We have a lot of issues so this is really about bringing people together,” said Haick Avakian, a 31-year-old accounts manager, as the second half of the match began.

That rugby has acted as a unifier is a small miracle. The sport was long associated with South Africa’s white minority. Black players were banned from competing under apartheid and the country’s national side was excluded from international tournaments. A key factor in the current breadth of support for the Springboks is the diversity of the team. Only around half the players are white.

A second factor is Kolisi, who came from desperate poverty to fight his way up through the intensely competitive ranks of South African rugby to became the first black player to captain the international side.

The 28-year-old is married to a white woman, has adopted his two half siblings, has two children of his own and represents the progress that, though undeniably patchy, South Africa has made over recent decades.

Fans celebrate at the Pirates Rugby Club in Johannesburg. Photograph: Jérôme Delay/AP

“He’s just a great example of what South Africa and South Africans can do if we try,” said David Dlamini, 55, as the crowd cheered a missed England penalty.

With 10 minutes to go, the shouts of “Go, Bokke” grew louder, the crowd denser. Images of the word “South” being etched on to the Webb Ellis trophy in preparation for the now certain victory raised further cheers.

Then the final whistle blew. Beer was flung into the air, flags waved, Shosholoza rang out again. Two security guards danced, their nightsticks held in the air. A portly older woman in a purple dress shuffled happily next to a man in a bright yellow suit. Grinning, jumping teenagers exchanged elaborate series of fist bumps and high fives. Below the screen, now showing close-ups of the jubilant Springboks, two children skipped happily, the backs of their T-shirts bearing a simple legend: “South Africa, your time is now.”