Fifty nine people were arrested after post-election protests in a Johannesburg township turned violent.
Police said they used rubber bullets and stun grenades to disperse protesters in the impoverished Alexandra area who had burned tyres and barricaded roads.
The army was deployed in the area, which is now calm.
The country's ruling African National Congress won the national election with 62 percent of the votes.
The provisional result shows the ANC's main rival, the Democratic Alliance, took 22 percent, while the ultra-left Economic Freedom Fighters managed 6 percent.