Police believe the three had been deliberately targeted and admit that the gangland-style attack ‘doesn't have the hallmarks of a random act’.
The 21-year-old man was gunned down at an MoT and car-repair centre in Balmore Road in the Lambhill area.
The shooting is thought to have occurred after a high-speed chase which ended at the garage.
Residents reported hearing bursts of "rapid gunshots" similar to that of an automatic weapon being fired.
Two other men, aged 41 and 26, remained in hospital last night with gunshot wounds. However, investigators have not yet linked the incident to another shooting that occurred in the city's Woodlands Road on Tuesday.
It is understood that Applerow Motors is owned by a member of the Lyons family. In the past nine months, relative Eddie Lyons Jnr has been shot in the face, run over and had his £40,000 car torched.
Detective Superintendent Campbell Corrigan, of Strathclyde Police, said: "From the sketchy information I have to hand at the moment, it would look like something that has perhaps been planned.
"I'm going to take into account that it may be something to do with a wider criminal ongoing feud, or perhaps something that has happened in all that."
Police were last night hunting two men in dark clothing who fled in a light blue car.