The ruling African National Congress (ANC) hovered near a 67% victory in preliminary election results released by noon on Friday.
The ANC had secured 9 523 311 votes by midday, which calculates into 67,2% of the vote, according to data interpreted by the Independent Electoral Commission (IEC).
It needs 66,6% for a two-thirds majority which would make it possible for the ruling party to change the Constitution.
By midday, 14 368 897 votes had been counted from Wednesday's elections in which a record 23 181 997 voters registered.
After the vote crossed the halfway mark at mid-morning, the pace quickened with more than one-million votes counted in an hour, compared to the slower pace through the night and into the early hours of Friday morning.
The Democratic Alliance's (DA's) status as the official opposition remained safe with 2 173 856 votes (15,34%).
The newly formed Congress of the People (Cope) was a distant third with 1 067 640 votes (7,53%).
The Inkatha Freedom Party was fourth with 617 146 votes (4,35%), followed by the Independent Democrats dropping slightly with 125 488 votes (0,89%).
In the hotly contested Western Cape, the DA remained on top with 602 142 votes (48,34%), followed by the ANC with 396 493
Cope featured in a distant third in that province with 111 615
The total number of votes cast is not yet known.
The IEC had estimated voter turn-out to be about 77%.