New National candidate Shane Reti has won the Whangarei electorate with a strong margin.
Mr Reti had a lead of almost 10,000 votes with 75 per cent of the vote counted.
His closest rival, lawyer Kelly Ellis, had 4500 votes.
The seat had been held by former housing minister Phil Heatley for 15 years.
Mr Reti said he had the benefit of campaigning for the seat for the past six months.
"Of the upper North Island, I was the candidate selected first so I had more time than anyone else.. I was full-time [campaigning] for six months."
Mr Reti, a doctor, had been living in Boston, on a Harkness Fellowship to Harvard. He examined community health issues such as how to improve appointment rates at public hospitals, and once offered to fund a $70,000 survey on fluoride out of his own pocket.
He said his plan was to focus on the region's economic developments, particularly job creation. "I want to give people real choices and the money in their pockets to make those choices."
Mr Reti said the campaign had been a respectful one.
National list MP Paul Foster-Bell had also sought the seat.