THE POLICE sirens announced them. At around three yesterday afternoon on a sunny and bitterly cold afternoon, the South African team bus swept down the highway for an afternoon training session. Through the tinted windows it was easy to make out the players lounging in their seats, silver headphones wrapped around their ears, watching the city go by.

Today, on the anniversary of the Soweto uprising, South Africa play Uruguay in what might be the turning point of their World Cup. The occasion is one of those strange occasions when sport and history combine to create a mood that can seem providential.

Youth Day is a public holiday in Johannesburg but over the decades since fierce clashes between Sowetan students and police left hundreds dead it has lost something of its solemnity. "Booze, bashes and other unmentionables now characterise how both young and old celebrate this day", scolded the editorial in Tuesday's edition of The Sowetan.

“We are in danger of forgetting our history. We do not guard our gains and victories. We let our memories scatter in the wind”.

If the morning is given over to remembrance of the fallen students, then tonight will revolve around Bafana Bafana. Race was the defining characteristic of the 1995 South Africa Rugby World Cup team, with the presence of Chester Williams preventing a completely white rugby squad.

And although this South African football team is, with the exception of beanpole defender Matthew Booth, exclusively black, it might be considered a mark of progress that the fact is rarely remarked upon.

However, today’s anniversary will bring the decades of oppression and protest into sharper focus and South Africa’s football team cannot but be conscious of what they represent to the citizens in this city, let alone throughout the country. As they made their way to the stadium, cars honked and those black Johannesburgers that always seem to be walking on the grass verges or climbing down embankments on the motorway system stopped and waved excitedly at the heroes.

A victory tonight would send an unimaginable surge of civic pride and optimism across the city, from the township of Alexandria to the silver service restaurants in Sandton.

Johannesburg is prone to snap power cuts because of depleted electrical reserves but the mere sight of the South African team has been like an electrical jolt. It was essential that they scored a goal in the opening match against Mexico and Siphiwe Tshabalala’s belter was so clean and emphatic – it was a proper goal – that it was easy to imagine South Africa embarking on a fantasy World Cup where they take on all comers simply because the popular mood wants it to be so. Tonight, though, the emotion of the people will not be enough.

“Uruguay are a physical side, very organised at the back. They play with three central defenders and they have good attacking players and it is going to be difficult,” warned Steven Pienaar, the undisputed idol of the national side.

His team-mate Siboniso Gaxo admitted that South Africa cannot afford to start as nervously as they did in the opening match. “We need to start on a high and we are hoping that the outcome will be on our side because qualifying will be the most important thing that ever happened in South African football.”

The peaks keep changing for South Africa in this tournament. Should they qualify for the second round, then making it to the quarter-finals will be the new dream. And so on.

Bafana Bafana are the one constant for local people, the one element of the vast circus that everyone approves of. Everywhere, people are still trying to make sense of whether this World Cup is actually working or not. At the Fifa press conferences, the smooth men in blazers are hedging their bets. Local anger at the stipulations which Fifa placed on South Africa is becoming louder.

"South Africa agreed to a shocking 17 guarantees that included Fifa not paying any of the usual taxes, that hospital beds would be reserved for some eventuality, that special courts would be set up, that hawkers be evicted from South Africa," wrote Andile Mngxitana, a columnist in The Sowetan.

“I struggle to understand what good the World Cup is for. We are paying more than R100 billion (€10.67bn) for this World Cup. We shall pay, our children shall pay and those poor rural women will also pay. That is what makes this whole thing so evil”.

And there is something menacing and shadowy about the way that Fifa conducts itself. It could be that in the months and years after the World Cup vanishes from South Africa, leaving only tinsel on the roads and a gigantic bill, the legacy of this World Cup will be one of bitterness and debt.

But right now, at this moment, when the people of Soweto – perhaps the most famous and evocative place name in South African culture – prepare to nod to the events of a winter’s morning 34 years ago and then tonight cheer their lungs off for the team that is supposed to symbolise the best of South Africa’s tomorrows, it seems churlish to argue that this tournament has not brought some good to a blighted city.

All eyes will be on the bright lights of Loftus Versfeld Stadium in Pretoria tonight. South African goals – a South African win – would be literally priceless. But no matter what happens, the mood around Johannesburg tonight will be infinitely better than it was on the June night 34 years ago when dozens of Johannesburg school children lay dead.