The updated data provided by the Electoral Commission of South Africa (ECSA) specify that the African National Congress (ANC) is followed by the Democratic Alliance (AD), with 24.17 percent and the Economic Freedom Fighters (EFF), with 9.14 percent of voters.
The party, which appeals mainly to young voters and the poor, has centred its election campaign on its policy of seizing land from largely white owners to give to poor blacks.
Despite the demise of apartheid 25 years ago, South Africa remains divided by economic inequality.
The African National Congress, or ANC, that led the fight against Apartheid, governed the country since 1994 - but it's become increasingly unpopular after a long list of ANC officials were accused of corruption and mismanagement amid economic woes.
The party has been tarnished by widespread corruption scandals and a national unemployment rate of 27% that has left many voters disillusioned.
The party's head of elections, Fikile Mbalula, told reporters on Thursday night that if Ramaphosa had not ousted his predecessor, Jacob Zuma, as leader of both the party and the nation during a fierce three-month struggle for power in late 2017 and early 2018, the ANC might have polled as low as 40%.
Analysts have said that a poor showing for the ANC would embolden opponents of President Cyril Ramaphosa and risk a potential leadership challenge against him.
A new projection by the respected South Africa's Council for Scientific and Industrial Research forecast the ANC would win with 57 percent - a five percentage point drop from the last election in 2014.
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Hundreds of ANC ruling party supporters from the Mangosothu University of Technology.
"It might be a reduced majority", said political scientist Collette Schulz-Herzenberg from Stellenbosch University.
Electoral officials say a tally from 90% of the vote may be announced later Thursday, although final results may not be announced until Saturday.
Andrew Harding says the party's stance has forced the ANC to consider drastic measures to transfer more land, more quickly, into black hands, which has resulted in a pledge to conduct land expropriation without compensation.
The partial results showed ANC ahead in Gauteng province, where South Africa's biggest city Johannesburg and the administrative capital Pretoria are located, while the DA-led in the Western Cape, home to Cape Town, where parliament resides.
Polling stations opened at 07 hours country-wide and are expected to close at 21 hours.
"About 26.8 million voters were registered to cast their ballots but only an estimated 65 percent did so". It had 23% of the vote, about the same share it received previously.
Mr. Ramaphosa, a wealthy businessman and former union leader, is more popular than his party.
Younger people, in particular, have abandoned the system, with only 19 per cent of the youngest eligible voters (18 and 19 years old) registering to vote this time, a much smaller percentage than in previous elections.