The Black Caps have reached the pinnacle of test cricket's world rankings for the first time, but their hold on the position could prove to be short-lived.
New Zealand beat Pakistan by an innings and 176 runs on Wednesday to complete an emphatic clean sweep of their test summer, after also easing past the West Indies 2-0.
The remarkable summer comes off the back of 17 unbeaten test matches on home soil over the past three years; their last loss coming in March 2017 against South Africa in Wellington.
While the new ranking looks well-deserved, New Zealand's place on the ladder could change in a matter of weeks and hinges on the outcome of Australia's home series against India.
After bowling India out for 36 as part of a series-opening eight wicket thrashing, Australia were soon humbled as a Virat Kohli-less India bounced back to win by the same result in the return fixture.
Australian Captain Tim Paine congratulates Ajinkya Rahane on his side's eight wicket victory in the second test. Photo / Photosport
Now there are two tests left in the series, the first of those beginning today, which will decide the future of the Black Caps' world ranking.
Here's what happens under the four possible scenarios in play in that series.
Australia win series
This is as simple as it gets: a series win for Australia will see Tim Paine's side go back ahead of New Zealand on the ICC's test rankings.
India win series 2-1
This result would require the sides to draw one fixture while India wins the other. While an impressive feat in itself, this result would not be enough for India to leap-frog the Black Caps.
India win series 3-1
Two wins for India would complete a remarkable turnaround for the tourists after their huge loss in game one and without the services of superstar performer Kohli. But stranger things have happened in cricket. A 3-1 win would see India take top spot.
A drawn Australia-India series would see New Zealand remain number one in the world.
Black Caps fans will now be crossing their fingers and rooting for a highly-competitive pair of test matches where India perform well, but not too well. Either that, or they'll be praying for the rain to get there - and to get there fast.