A number of the man's belongings were taken, including his black wallet containing his identification, cheque and deposit books and men's jewellery.
During the incident the man sustained a nasty head wound after being hit with a blunt object, and was also kicked in the head.
The victim was now recovering after his ordeal, police said.
The offenders were described as men wearing dark-coloured, hooded sweatshirts.
They were heavily disguised wearing bandannas across their faces, had their hoods up and wore gloves.
Two of them were believed to be aged in their teens, with the third in his early to mid-20s.
The ethnicity of the men is unknown.
Detective Sergeant Craig Vining said police believed the incident was unprovoked, but there could be a possibility the victim knew the offenders.
Police said it was likely the offenders travelled to the Onekawa property in a vehicle, and were asking for sightings of any cars entering and exiting Niven St between about 2.45am and 3.45am on Monday.
If you have a premises accessible to Niven St with CCTV which shows the street, contact the police.
In January an elderly Napier man had a finger amputated after a confrontation with two male intruders.
The incident occurred after the men tried to gain entry into the 76-year-old resident's home in Ahuriri, about 1am on January 16.
The victim needed his finger amputated as a result of trying to prevent the men entering his home.
- Contact Hawke's Bay police on 831 0700 or Crimestoppers on 0800 555 111 with information.
