A man suffered critical injuries after the car he was driving hit a tree near Little River in Christchurch on Monday.
Firefighters arrived at the scene on Christchurch Akaroa Rd about 1pm and found the Christchurch man out of the vehicle.
An off-duty firefighter riding his motorbike came across the crash and helped the man before others emergency services arrived.
Little River chief fire officer Dave Irving said they are unsure if he pulled the man from the vehicle or he did so on his own.
"We are not sure if he was assisted out or the adrenalin helped him get out of the vehicle, we didn't have that conversation, but we found him [the driver] lying on the ground with some very serious injuries," he said.
He was taken to Christchurch Hospital by ambulance.
The serious crash unit is investigating.