The victim was walking ahead of his friends on Kendal Street, near Myrtle Street, when the suspect jumped out of a car, approached him and challenged him to a fight, police said.
A female who was driving the car handed the suspect a sharp object, which he used to stab the victim in the shoulder and back.
The suspect was last seen fleeing east onto Monte Vista Avenue in a silver or black car similar to a Saturn, police said.
The victim was taken to a hospital for treatment.
The suspect was described only as a Hispanic male with a muscular build. Anyone with information about the stabbing is urged to call police at (707) 449-5200.