The killer forced his way into the third-floor flat in Dumbarton Road, Yoker, Glasgow, and attacked the 52-year-old.
Police believe the victim was visiting the homeowner, when the intruder burst in and killed him.
Neighbours said the brutal murder had rocked their close-knit community.
One local resident said: "Dumbarton Road isn't exactly quiet.
"But I just don't understand how this could happen in our street, on our doorstep."
The alarm was raised shortly before 1am yesterday when officers were called to reports of a disturbance. The man died at the scene.
Officers said the killing was "not a random act" and they appealed for any witnesses to come forward.
Cathy Callan, who lives in the next block of flats, said she heard a "commotion" during the night.
She said: "I heard a female screaming, that's what woke me up.
"Then the dog was barking, that's when I looked outside and saw the ambulances and police arriving. It's awful."
A team of officers from the Specialist Crime Division were at the scene as the murder hunt got under way.
Detective Chief Inspector Jim Smith, said: "Our inquiries are at an early stage to establish the circumstances which led to the death of this man.
"Although a post mortem examination will be carried out, we are treating his death as murder.
"At this time, it is believed that a man arrived at the flat around 12.50am, forced his way into the house and assaulted the victim who was not the householder.
"It is not clear what the motive was but it was not a random act. It would appear that the victim was the intended target. However at this time it is unclear why."
Witnesses, or anyone who heard a disturbance at the flats, have been urged to contact police.
Police said the suspect is a white male, around 5ft 6in, of medium to skinny build with short fair hair.