Homicide Squad detectives are investigating the circumstances surrounding the death of a man in Frankston last night.
It's believed a 58-year-old woman and her 17-year-old son were at their Dandenong Road West home when there was a knock on the door about 11pm.
The woman answered the door and was allegedly confronted by a 45-year-old male with a knife.
A scuffle ensured and the teen came to check on his mother.
A further confrontation between the two males has occurred, resulting in the 45-year-old man being fatally stabbed in the upper body.
The man died at the scene and residents subsequently called police.
Neither the woman or her son were physically injured during the incident.
Detectives from the Homicide Squad are investigating and at this stage, believe the deceased man was known to the woman.
Police are not looking for anyone else in relation to the incident and there is no evidence of any ongoing threat to the community.
The woman and the teenage boy are currently with police assisting with enquiries.
Anyone with information about the incident is urged to call Crime Stoppers on 1800 333 000 or log onto www.crimestoppersvic.com.au
