The outage was reported at about 7:55 a.m. and affected neighborhoods in the city as far north as Laurel Heights and as far south as Haight-Ashbury, PG&E spokeswoman Brittany McKannay said.
Crews responded and had power restored to all customers by about 9:15 a.m., McKannay said.
She said crews will remain in the neighborhood this morning to try to determine the cause of the outage.
Another outage left more than 10,200 PG&E customers without power in the same area of San Francisco on Thursday night. Power was restored to those customers by about 11:30 p.m.
McKannay said it was not yet clear if the two outages were related.