The carjacking was reported around 3:30 a.m. in the first block of Jones Street.
Two men were sitting in the car when three suspects approached. One of the suspects opened the driver's side door, pointed a black semi-automatic handgun at one of the victims, and demanded his property, according to police.
The victim handed his cellphone and wallet to the suspect, who then ordered the pair out of the vehicle, police said.
As the victim got out of the car, he was struck in the face with the gun. The suspects, three men believed to be in their 20s, then got into the car and drove away. They had not been found as of this morning, according to police.
Anyone with information about the carjacking is asked to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411.