John fell back and hit his head on the ground after being punched, sustaining a bump to his head and a scraped elbow.
He suffered a broken facial bone and required surgery to rejoin a muscle and tendon. His eye remains swollen shut.
The incident unfolded when John went out to his shed, near the house, on Birchs Rd.
He saw a teenager in the shed with a petrol can. John told him to put it down, and the teenager dropped it and fled, joined by three or four others John had not initially seen.
They ran down an adjacent driveway leaving a car, believed to have been stolen, parked behind the shed.
John called 111 on his cellphone and followed them down the driveway, so he could tell the operator where they were going.
Then to John's surprise they came back "at full speed" towards him to get back to the car.
One swung a punch, hitting John side-on, causing him to fall. He had to quickly move his legs as the car reversed back out to the road.
John told the 111 operator he had been hit, saying "and there's quite a bit of blood."
"They were the sort of kids you see kicking a rugby ball down at the beach to impress the girls. That's what I think they should have been doing," John said.
"(It is) just sad, that four to five young lads aren't at the best place for their age at this stage in their lives."
Police said they have no suspects.
• If anyone has any information on the assault or knows the teenagers involved, phone 105 and quote file number 210119/8268.
- starnews.co.nz
