Counting began after South Africans voted Wednesday in an election seen as their country's most important since apartheid ended 30 years ago.
The election was held on one day and polls closed after 14 hours of voting at more than 23,000 stations across South Africa's nine provinces.
Officials were gearing up for counting but the final results are not expected for days.
The independent electoral commission that runs the election said they would be announced by Sunday.
At stake is the three-decade dominance of the African National Congress party, which led South Africa out of apartheid's brutal white minority rule and to democracy in 1994.
The party is now the target of a new generation of discontent in a country of 62 million people — half of whom are estimated to be living in poverty.
After winning six successive national elections, several opinion polls have put the ANC's support at less than 50% before this vote, an unprecedented drop.
It might lose its majority in Parliament for the first time, although it's widely expected to hold the most seats.
