Scott Becker (Christchurch) and Donald (Dunedin) beat Sean Becker (Kyeburn) and Bridget Becker (Melbourne) 9-6 in the final at the Naseby International Curling Rink.
Scott Becker and Donald will represent New Zealand at the world mixed pairs championships in Italy next April.
"I'm certainly pleased, "Scott said.
"It is good to get one up over Sean and Bridget."
It was a significant win because Sean and Bridget were the defending champions and finished eighth from 26 teams at the world championships in Finland this year.
This discipline paid dividends yesterday when the pressure went on in the final.
The third end was crucial with the scores level at 2-2 after two of the eight ends.
A four on the third end proved decisive for Scott Becker and Donald.
Scott Becker and Donald consolidated their position by scoring two shots on the next three ends to lead 8-4 with just two ends left.
Scott Becker and Donald led 9-4 after seven ends and had a five-point cushion before the final end.
In the semifinals, Scott Becker and Donald had a comfortable 13-1 win over the Ranfurly pair of Warren Kearney and Marisa Jones.
The other semifinal was closer, with Sean and Bridget Becker needing the extra end to beat the Maniototo combination of Warren Dobson and Cass Becker 8-6.
Cass is Sean's wife and had an inside knowledge of the tactics her husband would use in the game.
Semifinals: Scott Becker (Christchurch), Brydie Donald (Dunedin) 13, Warren Kearney, Marisa Jones (Ranfurly) 1; Sean Becker (Kyeburn), Bridget Becker (Melbourne) 8, Warren Dobson (Ranfurly), Cass Becker (Kyeburn) 6.
Final: Scott Becker, Brydie Donald 9, Sean and Bridget Becker 6.
