A Pyes Pa Rd resident said he and his wife were woken by an "almighty bang" and shaking of their house.
"It sounded and felt like it was an earthquake and as I rolled over to check I saw the time and it was bang on 4.30am."
The man said his wife then heard someone screaming out for help and found a car resting on the passenger door side in the culvert beside the main road.
"A man who must have been flung from the car was lying underneath near the back section of the car. I could only see his head and the car was resting on his chest.
"While the injured man was breathing he was unresponsive and clearly in a bad way."
The resident said another man driving home from work also stopped in assist after he described seeing the crashed car "tumbling down the road" towards his vehicle.
"We used a jack to lift the car slightly to take the pressure off the injured driver's chest. "
The distressed female occupant was in a lot of pain after she had fractured her femur above the knee during the crash, he said.
The resident said the crashed vehicle hit a shelter belt beside a fence on his neighbours' property and narrowly missed a power pole before it came to rest in the culvert.
"If the stopped motorist had been about 10 seconds earlier in his journey home the car could easily have collected his vehicle as it tumbled down the road," he said.
The neighbouring couple also assisted and tried to comfort the injured woman who was screaming in pain and did not want to be touched until emergency services staff arrived.
The couple said the impact of crash resulted in their mailbox being flung high into the air, landing in their front yard, mere metres from the front door.
"If the fence wasn't there the car could have ended up crashing into our house, "they said.
Police are still investigating the cause of the crash and Tauranga Hospital spokesperson said the 22-year-old injured woman was in a stable condition in a ward.
The 29-year-old male patient was treated and discharged.
