Harete Hipango spent almost double her nearest rival on the campaign which got her elected MP for Whanganui.
As a National Party candidate in last year's general election, Ms Hipango spent $23,856 on advertising compared with the $12,150 spent by Labour Party candidate Steph Lewis.
Donation and expenses returnsreveal Ms Hipango received $39,316 for her campaign, mainly from the New Zealand National Party. Donations also came from Holland Memorial Trust and Taumaha Trust.
Ms Lewis received $31,487 in donations: $3000 from the New Zealand Labour Party and $28,487 from the party's local branch.
The two front-runners were contesting the seat for the first time, after the retirement of four-term MP Chester Borrows. Ms Hipango received 16,751 votes, comfortably ahead of Ms Lewis' 15,045.
The minor party candidates in the Whanganui seat declared no donations of more than $1500 and spent little or no money on their campaigns.
Green Party candidate Nicola Patrick spent $461 on advertising and New Zealand First Candidate Reg Skipworth spent $75 on business cards.
Act's Alan Davidson spent no money.
In the Te Tai Hauauru seat, winner Adrian Rurawhe spent $18,330 promoting his campaign, slightly more than nearest rival Howie Tamati whose advertising campaign cost him $18,037.