Emergency services were called to Robertson St in Richmond just after 3am to find a person suffering from severe injuries.
A police spokeswoman confirmed the victim was taken to Southland Hospital shortly after the assault and remained in a serious condition.
A neighbour, who wished to remain anonymous, said it was not the first time police attended the nearby property.
"It sounded like a ruckus so we looked out the window and there were two cop cars and an ambulance parked outside."
Violence was not an unusual occurrence at the address.
Just a week ago, police were seen responding to an incident at that same address.
"It’s a pretty quiet street but there’s always something going on at that house.
"If there’s ever anything, it comes from there," the neighbour said.
There were often people coming in and out of the property "flat out", however, neighbours knew little about the occupants other than there were some young people living there and an older man.
Police were speaking to a male believed to be connected to the incident.
However, they were unable to comment on whether officers had attended any previous incidents at the address.
The investigation was still in its early stages and inquiries into the circumstances surrounding the assault were ongoing.
