South Africa’s controversial president, Jacob Zuma, is well known for his antipathy towards urban black intellectuals, whom he labels “the clever blacks”.

In 2014, when he was asked about public concerns that he had used state funds to build himself a £13m palace in his home village in rural KwaZulu Natal, he replied that only “very clever and bright people” cared about the issue. In a speech in November 2012, Zuma slammed urban blacks “who become too clever”, saying: “They become the most eloquent in criticising themselves about their own traditions and everything.”

Last week, the “clever blacks” had their revenge on Zuma, delivering the heaviest electoral loss to Nelson Mandela’s African National Congress since democracy dawned in 1994 while setting up a mighty contest for national elections in 2019.

Although the ANC retained massive support in rural South Africa, its losses in urban areas were shocking and comprehensive. In Nelson Mandela Bay, the coastal city renamed in honour of South Africa’s most famous son, voters rejected the ANC and gave their votes to the opposition Democratic Alliance. Just 10 years ago, the ANC got 66% of the vote in the city famous for its struggle against apartheid. It polled a disappointing 40% last week.

Yesterday, Pretoria (in the process of being renamed Tshwane), the executive capital of the country, was set to be run by an opposition coalition after the ANC came in at a paltry 41% of the vote behind the DA. The parliamentary capital, Cape Town, has been in opposition hands for more than a decade. The African continent’s economic powerhouse, Johannesburg, saw the ANC lose its majority as opposition parties started coalition talks there too.

The national story tells a similarly depressing story for the ANC. In local elections in 2006, the party got 66.3% votes nationwide. The DA took 14.8%. Last week, the ANC reached just under 54% and the main opposition DA stood at 27%.

Wednesday’s election was a major turning point for the ANC and for South Africa. Last October, ANC general secretary, Gwede Mantashe, warned a party policy conference that were its support to plunge below 60% this year it would mark a “psychological and political turning point”.

That moment has now arrived as the party that led the international liberation struggle against apartheid failed to convince its core urban constituency to vote for it in significant numbers. In urban townships such as Soweto, an ANC stronghold, voter turnout was as low as 46%, while those who did turn up increasingly voted for the opposition DA and the radical three-year-old Economic Freedom Fighters formed by expelled former ANC Youth League firebrand Julius Malema.

This is a watershed moment because it means South Africa is no longer a country dominated by one party of liberation. For long, we were slowly inching towards being a proper, lively, multi-party system that holds power to account. We are now hurtling that way. It’s exhilarating.

Former ANC treasurer-general Mathews Phosa, a businessman and former Zuma ally, summed up the ANC’s losses thus: “We need to accept the reality that there are many young people who voted for the DA. Where do these people come from? They left the ANC and why did they leave the ANC? The clever blacks have spoken… The masses are punishing us with the weapon we won for them. The vote.”

It’s been a long time coming. Since Zuma came to power in 2007, the ANC has been racked by corruption scandals, infighting and splits. Economic mismanagement has plagued the Zuma administration, with unemployment rising from 21% to just over 26% since 2008. The economy has taken a beating, with projections by the Reserve Bank saying that there will be zero growth this year, while ratings agencies have threatened a credit rating downgrade.

To mask these failings, the ANC ran a negative and racist campaign that aimed to paint the opposition DA as the party of apartheid. Campaigning in Nelson Mandela Bay, Zuma called the DA “snakes, the children of the National party” and repeatedly referred to its young black leader as a puppet of whites.

Urban South Africans did not buy this scaremongering. As the memories of the Mandela years and the liberation struggle have faded, and the ANC’s internal troubles have spilled out into the open, so too has unquestioning faith in the country’s liberation party and its veterans such as Zuma. The legitimacy conferred upon them by the struggle is no longer a mask for their failings in a country that is now scarred by stories of rampant political corruption, crime and poverty.

The country now enters a new era of competitive politics in a terrain where once the ANC’s struggle credentials ensured it unparalleled success. Malema, the energetic young founder of the EFF, has won 8% of the national vote and is a kingmaker in Johannesburg and Tshwane. Malema says he predicts the ANC will not be governing South Africa when the country takes to the polls in the 2019 national government elections.

It is a claim that would have once been dismissed as a pipe dream. No longer. Even in its rural strongholds such as Limpopo, where Malema comes from, the ANC has slunk in way below its previous support levels. In Zuma’s rural home municipality, the ANC claimed 44.25% while the Inkatha Freedom party won with 54%.

What does it mean? The post-colonial African story is replete with tales of liberation movements that have stayed in power with one leader and one party despite losing the support of the people. Zimbabwe, just to the north of us, is a painful example of such a country; Mugabe and Zanu-PF have been in power for 36 years.

South Africa has broken with that narrative. First, Zuma is the fourth president of the country since 1994. Mandela broke with the “strong man” tradition by stepping down after one term. Now, with these results, a future where South Africa could be run by an opposition party is beginning to emerge. We could see this in the next national election in 2019 or in 2024.

It may be disconcerting for those of us who grew up with the ANC as the very heart of the South African political landscape, but it is not necessarily a bad thing. It heralds the maturation of our politics and the steady, welcome move towards a lively, competitive, responsive multi-party democracy. South Africans are using the ballot box to speak to their leaders and that can only be a good thing.

Justice Malala is a political commentator and author of We Have Now Begun Our Descent: How to Stop South Africa Losing its Way