An 18-year-old Henderson youth was found lying unconscious beside his wrecked car by a St John paramedic who was on the way home from work in the early hours of Sunday.
The crash was one of two on West Auckland roads that day that left drivers fighting for
their lives in Auckland City Hospital.
The youth suffered massive head injuries after being thrown from his car as it rolled on Edmonton Rd.
The passing paramedic noticed the car's headlights shining out from the bushes it crashed into and called emergency services at 2.30am.
Speed is thought to be a factor in the crash, which left the car lying on its side.
Sergeant Stu Kearns of the Waitemata serious crash unit said the youth was in a critical condition.
In a separate crash after midday on Sunday, a woman lost control of her car and crashed down a bank, missing several large trees and powerlines before landing beside a house at least 20 metres below.
Rescuers said it was lucky a resident heard the crash and called 111 because the car was not otherwise visible and it could have been some time before the woman was found.
A section of Scenic Drive was closed yesterday as police and firefighters removed the wreck.
Mr Kearns said the woman was taken to hospital critically ill but by last night had improved and was in a serious but stable condition.
She could not be cut from the car, because of its angle, so 12 rescue staff stabilised the vehicle with ropes before manoeuvring her out and on to a stretcher.
In both crashes, the drivers were the sole occupants of their vehicles.
