Mrs Dean said she set out to put herself and National's policies in front of as many people, face-to-face, as possible.
"If you want to win a seat, you have to work hard and that's all there is to it," she said.
The new electorate contained small communities and, to gain their confidence, she needed to meet as many people as she could - "so I did".
Waitaki is a new electorate that replaces parts of the Otago and Aoraki electorates, which no longer exist, and has the third-largest land area of all general electorates.
The former Playschool presenter and Waitaki district councillor was "chuffed" with the huge victory over Mr Parker, saying she seemed to have managed to get the confidence of people in the large electorate.
The challenge now was to live up to that and Saturday night was the "benchmark" for her, she said.
Mrs Dean was aware there was still some resentment that a large portion of South Canterbury had been brought into the new electorate.
She was no longer MP for just Otago - she had to gain the trust of South Canterbury.
"That's a challenge for me," she said.
One of the biggest roles she could have in Wellington, when legislation was being discussed, was to bring a provincial perspective to it.
A mother of three, Mrs Dean said she would "fight like mad" to keep young people in New Zealand and, if they went overseas, then fight to give them a reason to come back.
One of the highlights of her first term as an MP had been getting party pills reclassified under the Misuse of Drugs Act.
Mrs Dean was thrilled with her huge majority, saying she did not think it would be that large.
It meant she could move around the electorate with some confidence that what she stood for was what people were looking for.
There was a buoyant mood at National's Waitaki electorate party at the Kingsgate Hotel Brydone in Oamaru - even some of the drinks being served were blue.
There were whoops of joy and applause among a crowd of about 70 - along with streamers being popped - when Mrs Dean cut the celebratory chocolate cake, complete with blue stars, at 11.10pm.
Further down the street at the Foundation for the Blind hall, there was a much more subdued atmosphere at the Labour camp.
About 25 party faithful were present when Mr Parker announced about 9.10pm that he was going to call Mrs Dean to concede.
Mr Parker, who won the Otago seat from National's Gavan Herlihy in 2002 and was then defeated by Mrs Dean in 2005 (with a 1931 majority), said it was always going to be an impossible task to win the electorate vote.
Waitaki, with its current boundaries, was a safe National seat.
Labour had run a deliberate party vote-focused campaign rather than a personal vote campaign in Waitaki and he thanked campaign supporters for a "magnificent job" done.
It was not surprising there was a mood for change.
It was very rare for a party to win more than three consecutive terms.
The fact Labour had governed for three terms had been "fantastic" and New Zealand was a better place than it was nine years ago, Mr Parker said.
