Officers responded to a report of a stabbing in a parking lot in the 1400 block of Phoenix Drive at about 9:40 p.m., according to Fairfield police.
Arriving officers found an 18-year-old man who said he had been approached by two suspects between 18 and 20 years old, who asked him if he knew where to buy marijuana, police said.
When the victim said he didn't, the suspects chased him through a parking lot to the rear of an apartment building, where a second victim, 23 years old, was being attacked by two other suspects, police said.
A fight ensued, during which the 18-year-old man was stabbed, punched and kicked, police said.
Residents of the apartment building called 911.
The stabbing victim was taken to a hospital and reported to be in stable condition, police said. His injuries were not considered life threatening.
The second victim was not stabbed but was taken to a hospital to be treated for moderate injuries.
The four suspects climbed over a chain link fence and ran off toward Suisun City.
They were all described as 18 to 20 years old, ranging in height from 5 feet 8 inches to 6 feet tall, and weighing between 150 and 170 pounds. They were last seen wearing dark clothing.
One of the victims told police he used to associate with gang members, but it had not been determined if Saturday's attack was gang related.