UPDATE: Power has been restored to about 3000 Horsham Powercor customers whose supply was cut on Saturday afternoon.
A fault in Hamilton Road, Horsham caused power to be cut at about 5.40pm.
The fault also meant traffic lights were out in parts of the city, including in Dimboola Road where police were directing traffic.
Powercor estimated power would be restored by 7.30pm.
About 800 customers were back online by 7.15pm, while power to other areas was restored just before 7.30pm.
Powercor is still investigating the cause of the fault.