The robbery was reported at about 11:40 p.m. Monday in the 1700 block of Fulton Street.
The 35-year-old driver had just dropped off a pizza and was walking back to his car when he was approached by two suspects, one of whom simulated a gun in his pocket, according to police.
One of the suspects then punched the victim in the ear while the other pulled cash out of his shirt pocket, police said.
The pair then fled toward Central Avenue, police said.
The victim was injured but did not require hospitalization.
The suspects, described as two men in their early to mid-20s, had not been found as of this morning. Anyone with information about the robbery is asked to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411.