Police said officers were responding to a report of an assault in progress at about 7:22 p.m. in the 2600-block of West Devon Avenue.
Police said the suspect approached them with the knife and one officer fired a single shot and another officer then used a Taser on him.
The man was taken into custody and transported to a hospital for treatment, police said. One officer was transported to a hospital for observation.
Police originally said the suspect was not hit by gunfire but Monday morning they said he was grazed on his thigh.
The Civilian Office of Police Accountability is investigating.