All Northern Cape votes have been counted and declared that the ANC has won with 63%, the DA takes second place with 23% and EFF takes third place with 5% votes.

The vote counting of the remaining eight provinces is still underway.

The ANC's resounding lead in the elections firmed to 62.7 percent as vote counting neared the two-thirds mark by late afternoon on Thursday, with the DA at 22.4 percent.

Julius Malema's militant Economic Freedom Fighters was third with 4.9 percent of the vote --- predictably proving itself the upstart success of the elections.

In 2009 that role had belonged to the Congress of the People, but on Thursday Cope's support base was in tatters at less than one percent, and just behind that of the Freedom Front Plus.

Political analyst Steven Friedman saw a cautionary tale in the EFF's rapid rise.

"They will continue to attract media attention... but whether that has any impact on South African politics is another matter," he said.

The African National Congress was leading the race in all provinces bar the Western Cape, where the Democratic Alliance looked set to grow its outright majority significantly.

The party had garnered 57.3 percent of the vote, but the result could change because counting was still continuing in Mitchells Plain and Khayelitsha, two sprawling areas where the ANC has been seeking to claw back support.

Less than 60 percent of votes had been counted and the final tally in the province was expected around midnight.

In Gauteng, vote counting was slower than elsewhere. The ANC was at 52.5 percent compared to the DA, which hopes to rob the ruling party of an outright majority in the province, at 32 percent.

But these results could yet change dramatically as there were no final figures yet in Johannesburg metropolitan areas.

"We are quite humbled by the confidence and trust our people have shown," Gauteng ANC leader Nomvula Mokonyane said.

Electoral Commission of SA (IEC) chairwoman Pansy Tlakula cautioned that the results could still shift throughout the country because the smaller voting districts were those where counting had been completed first.

"This means that we can still anticipate significant movement during the course of the day," she said.

But Mokonyane said the ANC did not foresee its lead shrinking in the party's fifth landslide victory since the demise of apartheid.

"Nothing below 63 percent."

The IEC said several incidents of violence had marred what was largely a peaceful election, with a turnout far exceeding expectations.

An ANC member was killed outside a voting station in KwaDukuza, KwaZulu-Natal. ANC spokesman Jackson Mthembu said the party suspected a rival party was behind the killing.

"This comrade was killed while sitting at the ANC desk outside a voting station," he said.

Another person was shot in KwaMashu in KwaZulu-Natal.

The party results in KwaZulu-Natal showed the ANC far ahead at 64 percent. The IFP seemed set to be confirmed as a spent force in the province, with 13 percent.

According to the IEC, two people who posed as voters were arrested for an attack at a voting station in Tzaneen, Limpopo.

"They entered the station and attacked the police on duty, election officials and party agents, and damaged voting material," Tlakula said.

In Springs, on the East Rand, police found a ballot box containing 16 special votes. Police were investigating the matter.

"These remain isolated incidents which we are taking extremely seriously and, along with the police and party liaison committee partners, are investigating," Tlakula said.