Preliminary results of the regional council's Dunstan Ward by-election gave Dr Lawton a commanding lead on 7184 votes, almost 2000 votes head of Garry Kelliher on 5213.
The final results will be announced tomorrow once special votes are counted.
As of yesterday, about 33% of those enrolled in the ward had voted, but votes in transit to the processing centre and special votes had not been counted.
The by-election was called after Dr Lawton's mother Maggie Lawton died this year after a short battle with cancer.
Dr Lawton said it was a bittersweet moment to be filling the seat her mother was elected to only last year, but she was ready for the challenge.
''I never envisioned I would be having to do this, but when I put my name, I put it down to win so in that sense I am very happy.''
During the campaign, Dr Lawton said she meet a wide range of people from across the ward's geographic area
''I think this emphasis on the rural and urban divide is a bit overblown.
''The people I spoke to during the campaign were all mostly concerned about the same things, but maybe in slightly different ways.''
Water was one issue which people across the ward were concerned about, she said.
She thanked Mr Kelliher and said she appreciated the chance to listen to his ideas during the campaign.
Mr Kelliher said he was gutted about the result but wished Dr Lawton all the best.
He was humbled by the support he had received but was worried about the Dunstan constituency.
''I suppose we all bring different positions to the council. We all have different areas of expertise.''
It is the second defeat in a row for the former regional councillor who lost by five votes to Michael Laws at the local body elections last year.
He had not considered running at the next regional council election and said it would be challenge to convince his family running again was a good idea.
''We've still got plenty to keep us busy.''
A by-election for Dr Lawton's old Wanaka ward seat on the Queenstown Lakes District Council will be held from July 6 to July 28.
-Additional reporting by Jono Edwards
