Eskom confirmed on Saturday that South Africans would face stage 1 load shedding between 09:00 and 23:00 as a result of a shortage of capacity. Stage 1 allows for up to 1000MW to be shed on a rotational basis.
But the utility cannot yet say if SA will also face power rationing on Sunday, when South Africa takes on Japan in a Rugby World Cup quarter-final match at Tokyo Stadium.
"We will be in a better position to advise about the prognosis for load shedding for the rest of the weekend and the coming week later today [Saturday]," said Eskom.
Kick-off is at 12:15 SA time on Sunday.
Earlier in the week the utility blamed the current wave of power cuts, which began on Wednesday, on boiler leaks and the breakdown of a conveyor belt transporting coal to Medupi power station. Eskom also said delays in returning units that were on planned maintenance to service contributed to supply constraints, as did diesel shortages.
Diesel is used to run the utility's expensive open cycle gas turbines, which are used to meet peak demand or in an attempt to stave off load shedding.