UPDATED 4:52pm: West Auckland Police say without the intervention of a group of bystanders, an attack on a young woman could've ended very differently.

The woman has facial bruising and abrasions to her neck after the attack in New Lynn around 9:30 last night.

She was in her car at traffic lights on the corner of Hugh Brown and Great North Road when a man she didn't know tried to open her door.

She managed to drive off when the lights turned green, but the man came up to her car and opened the door again when she'd pulled over to call the police.

Area Commander, Inspector Scott Webb, says the man then punched her in the head and grabbed her by the throat.

He says a group of eight men at a nearby internet cafe rushed to intervene when the heard the woman's screams and the car horn.

Police are heaping praise on bystander Konrad Berking who ran to help the young woman. Berking says one of the group managed to chase the offender and tackled him to the ground.

"I've done the right thing. I don't want to take too much glory, it was a combined effort by all of us," he said. "I was just making sure the area was safe and sound."

Inspector Webb, says he can't praise the group of young men enough.

"We'll certainly be looking at recognising these guys in the near future for their actions. It was really, really good work. We would have to have a good look at all the facts, but potentially [we would award them] some sort of police recognition for their actions, be that at the police awards ceremony or something similar."

A 22-year-old man has been arrested and will appear in court today.