Police, ambulance officers and volunteer firefighters were called to State Highway 12 at Kaihu, 28km northwest of Dargaville, about 12.30pm yesterday.
Dargaville Constable Ewen Cumming said it looked like the car failed to take a moderate bend, crossed the centre line, went into a drain and then hit a power pole. It was raining at the time of the crash.
The Northland Rescue Helicopter landed at the local rugby ground where St John staff had stabilised the man in an ambulance. Cumming said the man - the only person in the car - was flown to Auckland Hospital.
Power was out to 165 customers for about nine minutes, but some were without power until at least 4pm.
Northland's road toll is 22 for the year to date. Last year's total was 27.