Officers responded to a restaurant near the Alliance gas station at state highways 1 and 92, where the victim was being treated by medical personnel at about 8:20 p.m., according to police.
The victim apparently had begun talking to a female driver of a Chrysler when a male occupant of the car confronted the victim for talking to the female. The two began fighting, when the suspect pulled a gun out and shot the victim in the arm, police said.
The suspect and female fled the scene in the Chrysler and were last seen driving east through the parking lot and then onto eastbound Highway 92.
The victim was transported to Stanford Hospital and is expected to survive, police said.
The suspect is described as a white man in his 20s or 30s, about 6 feet tall and 175 pounds. Anyone with information about the case is asked to call the Half Moon Bay Police Department at (650) 726-8286.