Nearly seventy-thousand businesses and homes were hit for the most part in the north of the central business district. Some surrounding suburbs were also affected.
A spokesperson for Energy Australia told AAP at around 6.40PM that they had been able to get power back through three cables that supply the city.
At around 4.45, a major fault struck four main cables that supply two sub-stations in the city.
Central Sydney was the scene of chaos because of the massive peak hour power failure. Major road links were closed, traffic lights were blacked out and hundreds of buildings were in darkness.
Fire services were overwhelmed by the number of calls about automatic fire alarms and people stuck in lifts around the city. Further gridlock was caused by the complete closure of the Sydney Harbour Tunnel and the Eastern Distributor road link.