So many voters flocked to the polls that many stations ran out of ballot papers.
Voters express frustration with ANC, but a large turnout favors the ruling party.
The polarizing ANC leader is expected to draw record numbers of voters to the polls in Wednesday's presidential race.
South Africa's ruling party candidate, Jacob Zuma, vows no constitutional changes ahead of April 22 vote.
The Congress of the People party officially launches on Tuesday. Its leaders – dissidents from the African National Congress – could usher in a more vibrant multiparty era.