Te Tai Tokerau MP Kelvin Davis probably thought his chance of ever leading the country had disappeared during Parliamentary coalition talks.
But the Labour Party deputy leader will have his hands on the steering wheel over the next few days, with both Prime Minister Jacinda Ardern and deputy Winston Peters (as Foreign Affairs Minister) attending the Apec conference in Vietnam.
Mr Davis took over, when Ms Ardern flew out on Thursday morning and his first duty will be question time in Parliament on Thursday afternoon.
He's prepared for the National Party Opposition to take advantage of the leaders' absence to unsettle the new Government, as it did during Tuesday's swearing-in ceremony.
"I'm sure they will try all sorts of strange tactics," admitted Mr Davis. "But they will have to take responsibility for their own behaviour.
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"We will play things with a straight bat - we want to get on with governing the country," the MP told Newshub.
Earlier this week, the Opposition threatened to block the appointment of Trevor Mallard as Speaker of the House, when they suggested the Government lacked the numbers to carry through.
National withdrew their challenge, in return for more select committee seats.
Under a Labour majority, Mr Davis would likely have been the Deputy Prime Minister, but he sacrificed his standing, as part of last month's coalition deal with Mr Peters/NZ First and the Green Party.
"There's no doubt, it's an honour to be Acting Prime Minister for five days and counting down," he said.
"I think my cousins up north will give me some stick for it. I'm sure they'll give me a hard time at the Kaitaia RSA tomorrow night."
Mr Davis has been fully briefed by the Department of Prime Minister and Cabinet, but expects few burning issues while Ms Ardern and Mr Peters are overseas.
"If there are any issues I need to deal with, they will brief me and we'll take it from there."
Mr Davis, 50, entered Parliament on the Labour list in 2008, but retired from politics in 2011, after losing three times to Hone Harawira for the Te Tai Tokerau seat.
He re-entered Parliament on the Labour list in 2014, when Shane Jones resigned and finally defeated Mr Harawira for Te Tai Tokerau at the general election later that year.
Mr Davis again defeated Mr Harawira by 4807 votes in the most recent election, and he now holds cabinet posts as Minister for Crown/Maori Relations, Minister of Corrections, Minister of Tourism and Associate Minister of Education.
His stint as Acting Prime Minister will end, when Ms Ardern returns to New Zealand next Thursday.