That's according to Fresno Police officers, who added that when they arrived, they broke up the fight and found that the man's stomach had been slashed.
Investigators are still trying to figure out if the wound came from the woman stabbing her boyfriend.
The fight happened around 8:45 pm Friday near N San Pablo Avenue and E McKenzie Avenue.
The man was taken to the hospital with injuries that are described as non-life threating.
The woman has been detained by police, and investigators will question her boyfriend at the hospital.