Around 6,700 customers lost power shortly before noon when a vehicle struck a pole at Leavenworth and Filbert streets.
PG&E estimates the remaining customers will have their power restored by early this evening, probably a little after 5 p.m., spokeswoman Tamar Sarkissian said.
The city's Nob Hill, Telegraph Hill and Russian Hill neighborhoods were affected, as well as Pier 39.