The woman had just parked her car in an alley when the gunman drove up in a white SUV, according to police.
The man, who had a female passenger, got out of his vehicle and asked the victim for directions before demanding her handbag, SDPD Officer Frank Cali said. She ran off, and the thief opened fire. He then jumped back in the SUV and sped off to the north along with his companion.
Medics took the victim, whose name was withheld, to Scripps Mercy Hospital in Hillcrest for treatment of an upper-arm wound.
She described the shooter as a dark-haired, heavyset Latino who appeared to be in his 40s. His companion was white and roughly the same age.