Officers were called to the 2200 block of Newton Avenue, near Sampson Street, about 3:15 p.m. Saturday and found the victim lying in the middle of the street, San Diego police Lt. Mike Hastings said.
The man was taken to a hospital and died a short time later, Hastings said. Release of his name was withheld pending family notification.
Hastings said the preliminary police investigation indicated the victim was stabbed during an altercation with the suspect in a nearby alley. The suspect chased the victim until he collapsed a few blocks away, and ran off before police arrived, according to the lieutenant.
Police described the suspect as Hispanic, 28 to 30 years old, 5 feet 10 and 200 pounds. He was wearing white shorts and no shirt.
Anyone with information on the incident to call the Homicide Unit at (619) 531-2293, or Crime Stoppers at (888) 580-8477.