Victor Zheng, 16, was stabbed at about 10:55 p.m. on Feb. 7 near the intersection of Capitol and De Montfort avenues, just off of Ocean Avenue, police Officer Albie Esparza said.
Zheng was walking with a friend when a male suspect approached and punched him multiple times, Esparza said.
The suspect then tried to flee but Zheng and his friend chased him while calling police, according to Esparza.
At some point during the pursuit, the suspect turned around and stabbed Zheng in the torso with a knife and then fled in a newer black two-door Honda with chrome rims, police said.
Zheng was taken to San Francisco General Hospital where he died about an hour later.
He had attended Balboa High School for his freshman and sophomore years, but opted to take a proficiency exam instead of returning for his junior year last fall, said Kevin Kerr, the school's principal.
Police today described the suspect as an Asian man around 18 or 19 years old who is about 5 feet 10 or 11 inches tall, weighs between 160-180 pounds, and had dark hair and eyes.
He was last seen wearing a black hooded sweatshirt, saggy blue jeans, and black tennis shoes, and may have a mole on his upper right cheek, police said.
Anyone with information about the case is urged to call Inspectors Martin, Morley or Cunningham with the Police Department's homicide detail at (415) 553-1145 or the police communications center at (415) 553-1071.
People wishing to remain anonymous can call the department's tip line at (415) 575-4444 or send a text message by entering 847411, typing SFPD and then the tip.