After failing the test, the motorist was asked to accompany Mr Hurley to Wanaka and, on the way, allegedly kicked the officer in the head and attempted to gouge his eye.
Wanaka sub-area commander Senior Sergeant Allan Grindell said Mr Hurley stopped the vehicle after the assault and restrained the man before continuing.
However, the man began "playing up" in the back seat again as the car approached the Makarora Country Cafe, so Mr Hurley pulled into the cafe forecourt, restrained him again and radioed for urgent assistance.
Two police cars and an ambulance were dispatched from Wanaka and the Makarora Rural Fire Force also responded.
Cafe co-owner David Howe and another staff member assisted Mr Hurley before the emergency services arrived.
"He just wanted some help. He wanted somebody else there to give him support really," Mr Howe said.
"[I was] observing to make sure the person he had under arrest was still breathing because he was lying down on the back seat. So, we just made sure that everyone was safe."
Mr Hurley had "a few bruise marks on his face and he had blood on him ... he was quite shaken up", Mr Howe said.
The arrested driver was taken by police to Wanaka police station and is likely to face charges relating to drink-driving and assault on a police officer.
Mr Grindell was unable to confirm the man's breath or blood alcohol readings.
Mr Hurley received treatment for his injuries at Wanaka's medical centre and was last night in "pretty good spirits for what's happened", Mr Grindell said.
An attack on a staff member was upsetting and a risk associated with rural policing.
"I think it just brings it home to us about taking extra care."
While the incident was not the sort commonly experienced by Wanaka officers, it highlighted the "unpredictability and difficulties" of managing people who have consumed large quantities of alcohol, Mr Grindell said.
Police are developing a prototype protective screen that would be fitted between the front seat and back seat of the vehicles of one and two-person stations for extra protection.
- Additional reporting Debbie Porteous.