The attack occurred at about 4 a.m. Thursday in the 2500 block of Sutter Street.
The 23-year-old victim was apparently using drugs with the suspect, a 46-year-old man, when he struck her with the butt of a handgun and then placed the barrel of the gun in her mouth, according to police.
The man did not shoot the woman, but sliced her face and hands with a knife before she was able to escape. She was taken to St. Francis Memorial Hospital where she was in stable condition as of today, police said.
The suspect fled and had not been found as of this morning. Anyone with information about the case is encouraged to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411.