Engineers have restored power to 20,500 properties in Ashton under Lyne and expect to restore the remaining 1,500 properties by 1am.
An earlier power cut affected 22,000 homes and businesses when another company damaged multiple underground power cables in the area.
The damaged cables operate at 33,000 volts serving a wide area, and engineers have been working to restore power by switching supplies to other parts of the network.
Electricity North West incident manager, Chris Fox said: "We've connected up a couple of large generators now, serving around 400 properties, and have more generators on the way, along with extra people to connect and manage them.
"We already have 30 engineers on site and we'll keep working to get people back on, while also continuing to repair the damaged cable through the night which we hope to have back up and running in the morning."
Electricity North West has sent a food van at The Royal Oak pub, Lees Road junction with Nook Lane serving free hot food and drinks to customers without power.
Electricity North West are also proactively contacting customers on its priority service register who may need additional support, and is asking people to contact them if they know of anyone who is medically dependant on electricity.
Please take care while driving as traffic lights may still be down in the area.
Updates are being posted on Twitter and Facebook for the latest information.
Photos: Engineers dig around the damaged cable to make it safe to repair, while other engineers work from our Heyrod substation to reroute supplies to restore power.