A young woman was punched in the head as she stood up to three men who tried to steal her car at a Kaikohe petrol station.
One of the offenders was knocked out when onlookers came to help the woman being assailed on the Z station's forecourt, around 11am on Saturday morning.
Kaikohe police have arrested one of the offenders and are looking for two others, possibly youths with gang affiliations, involved in the incident.
The woman was putting petrol in her car when she was confronted by at least two men who demanded her car keys.
One of them allegedly got into the car and she was punched when she dived into the passenger seat and tussled with him.
At that stage, chased by onlookers who had rushed to help, the offenders ran away.
One of them was knocked unconscious during the ensuing struggle to hold him, a police spokesman said.
It's not the first time the Kaikohe Z service station has been the centre of a stoush. On May 9, last year, members of the Tribesmen and the Bloods, or Thirteen BZ, gangs fought on the station's forecourt.
At least eight people were arrested and convicted over that brawl.