Detective Inspector Dave Lynch said it appeared an argument over music sparked the confrontation.
"I can't rule out the possibility of further charges or arrests but time will tell.
"The investigation is ongoing and we'd appreciate any assistance we can get from anyone who thinks they have information."
Emergency services were called to the Otara property just before 1am.
On arrival, police officers found Mr Davis dead on the driveway at the front of the property.
St John said an ambulance was sent to Fisher Crescent at 12.53am following reports an assault happened at the address, leading to a possible stabbing.
By the time paramedics arrived, it was believed Mr Davis was in cardiac arrest.
The house was cordoned off today as police investigated.
"We will get underway with a scene examination at the property today and continue trying to locate those people who we understand attended the party thrown to celebrate the 21st of a young woman [related] to Chevy Davis," said Detective Senior Sergeant Ross Ellwood of Counties Manukau Police.
The same street was the scene of another family tragedy around Christmas 2006.
Then, a mother of five was found dead in her home after suffering serious injuries in a domestic incident.
Police said anyone with information about this morning's incident should should call Counties Manukau Police on 021 191 0881 or Crimestoppers anonymously on 0800 555 111.
