Police say that two males got into an altercation in the Yonge Street and Elmwood Avenue area at about 4 p.m. on Saturday afternoon.
The victim was stabbed in the chest with "a sharp-edged weapon," before the suspect fled the scene.
Police say they caught up with the suspect quickly and arrested him.
The victim was taken to hospital with serious, but non-life threatening injuries.
A 19-year-old Toronto man faces six charges including attempted murder and carrying a concealed weapon. He was scheduled to appear in court on Sunday.