Final results were expected on Friday, but with about three-quarters of the ballots counted, the ANC had garnered a thumping 63% of the popular vote, spelling a parliamentary majority big enough to hand embattled President Jacob Zuma a second five-year term.
ANC spokesman Jackson Mthembu said the 102-year-old party — which has held power since helping to end apartheid in 1994 — would ultimately receive “an overwhelming mandate” from voters.
The ANC’s status as the party of liberation was drilled home by the recent 20th anniversary of democracy and the outpouring of emotion that accompanied the death of former president Mandela in December.
But with 63%, it would still fall short of the two-thirds majority needed to amend the constitution and will see its winning margin reduced for a second consecutive election, down from 66 percent at the last poll.
Meanwhile the main opposition party, the centrist Democratic Alliance, made rapid gains, boosted by a strong urban turnout.
It’s share of the vote rose to 23%, up from 17% at the last election in 2009, according to the incomplete results, and looked set to top the polls in Johannesburg and Cape Town.
DA leader Helen Zille told AFP early on Thursday that she expects the final tally to remain at 23%.
“We’ll see how it goes, of course we hope it will be more. We did as much as we could,” she said.
Julius Malema’s populist Economic Freedom Fighters gained five percent of the vote, less than a year after the party was formed.
Both DA and EFF support has been bolstered by a series of scandals surrounding Zuma and frustration at rampant poverty and poor public services.
Casting his ballot in his home village of Nkandla, Zuma predicted the “results will be very good”, but conceded the campaign had been “very challenging”.
Zuma has been a lightning rod for criticism of the ANC. He came to office facing rape and corruption charges and has most recently been pilloried for spending $ 23 million (17 million euros) of taxpayer money to upgrade his private home.
But voters appeared to put storied party before sullied president. “When it comes to national elections the vast majority of ANC supporters decide that their loyalty to the organization is greater than their loyalty to its current leadership,” said political commentator Steven Friedman.
A record 25 million voters registered for the elections amid mounting anger over joblessness, inequality and corruption.
Turnout is said to be over 70%, including hundreds of thousands of “born free” South Africans, who were registered to vote in a general election for the first time.
“People died for this right. They must not waste it,” said Nobel peace laureate Desmond Tutu, a liberation struggle veteran who has openly said he will not vote for the ANC this time.
US state department spokeswoman Jen Psaki congratulated South African voters “for exercising their democratic right to vote,” adding that Washington looked forward to working with the new government of the Republic of South Africa “to further strengthen our bilateral relations.”
The ballot was marred by isolated incidents of violence, including the killing of one ANC member at a polling station in KwaZulu-Natal province.
Pansy Tlakula, chairperson of the Independent Election Commission, said a number of complaints were being investigated.
But, she added, “we believe the credibility of the election has not been affected.” Public enterprises minister Malusi Gigaba told AFP the party will use its fresh electoral mandate to “radically” boost black business. “The fact of the matter is black South Africans continue to feel a sense of social injustice in terms of economic ownership patterns as well as the ownership of the land,” said the ANC number three, who is tipped to head the party one day.
“We need to implement programmes that are going radically to change that.”
Gigaba admitted ANC policies that forced existing white-owned businesses take on a proportion of black shareholders had created problems.
“We want a programme that creates a real legacy in the form of building industry,” the 42-year-old said.