A 22-year-old man who was allegedly harassed and stabbed by a father and his son in a Scarborough McDonald's drive-thru last weekend died of his injuries Friday.

Toronto police, who have already charged the two with aggravated assault and weapons-related offences, are now treating last weekend's incident as a homicide.

Police said Tyler McGill, 22, was in the drive-thru lane with his girlfriend around 3:30 a.m. when Danny Mohammad, 19, and Azard Mohammad, 45, allegedly struck McGill's car.

He apparently got out to confront them and was stabbed in the chest, police said.

He was rushed from the scene at McCowan Road and Eglinton Avenue to Sunnybrook hospital, where he underwent emergency surgery.

McGill remained in critical condition all week before succumbing to his injuries, police said.

A post-mortem examination Saturday determined McGill died from a stab wound to the chest.

Police said they arrested the two suspects shortly after the incident, and a weapon was recovered.

The accused both remain in custody and are scheduled to appear in court on Tuesday.