Police were called to the park on Notre-Dame Street and Mercier Avenue around 11:30 p.m. Friday.
According to police, a 20-year-old man was in the park with his girlfriend when he got into an argument with at least two other people.
Montreal police spokesperson Manuel Couture said during the altercation one of the suspects stabbed the 20-year-old with a sharp object in the upper body, causing major injuries.
“We still don’t know what caused the argument,” Couture said.
The victim was rushed to hospital in critical condition but has since been stabilised.
“His life is now out of danger,” Couture said.
One suspect, a 16-year-old man, was arrested on site.
Couture credits a fast response time by officers for the arrest.
“They responded quickly and so they were able to arrest a suspect at the scene.”
A second suspect, a 17-year-old man, was arrested a few streets away with the help of the Canine Unit.
Both men are being detained and are expected to meet with investigators Saturday afternoon.