An Indian man was stabbed by his Filipino flatmate over his "stinking" shoes, the Milan police said, adding the 19-year-old jobless attacker was arrested.
The 47-year-old man, identified only as A.S., is still in a critical condition.
He was taken to Milan's Niguarda hospital where he underwent surgery and suffered four heart attacks.
The man was found by police in a pool of blood at the untidy flat with deep stab wounds to his chest and an arm.
The Filipino, Renzo Micalat, who was hiding in the attic, had allegedly rinsed the blood off the knife used in the attack, and was trying to change his blood-stained clothes when police arrived.
Micalat allegedly launched the frenzied attack after becoming enraged by a pair of shoes belonging to the Indian which he claimed "stank", according to investigators.
Micalat has an Italian residency permit and both he and the Indian have no criminal convictions.