A press release said a constable with the K-9 unit came across two men fighting in the south alley of Idywyld Drive North and 32nd Street West around 7 p.m.
Police say a man wearing a red shirt and ball cap ran away in the alley after the officer drove up to them.
The officer went over to the injured man and found him suffering from numerous stab wounds.
The 42-year-old victim was taken to the hospital with serious, life-threatening injuries. He is now in stable condition.
Officers from the Serious Assault Unit were called out to the scene and are carrying on with the investigation.
The suspect was not located and is unknown at this time.
Anyone with information on this incident is asked to contact the Saskatoon Police Service at 306-975-8300 or CrimeStoppers at 1-800-222-8477.