A 33-year-old man was stabbed in the heart when he bumped into someone while walking and texting downtown.
The victim was walking along Yonge Street, just north of Dundas, just after midnight on Wednesday.
The suspect and his friend attacked the victim.
Initially the victim was able to defend himself.
One of the suspects then stabbed the victim in the chest.
The victim was taken to hospital where he is in critical but stable condition.
One of the alleged attackers was arrested shortly after the incident.
Mohamed Ali, 27, of Toronto, has been charged with attempted murder and aggravated assault.
Police are still searching for the second attacker. He is described as white, five-foot-eight with short, dark hair and a chinstrap beard. He was wearing a black and white sweater.
Police believe he may be familiar to people who frequent the Yonge and Dundas or Yonge and Gerrard area.