After upsetting tournament favourites Belgium 5-4 on Wednesday, the Black Sticks have continued the Four Nations winning way against Japan.
A third-quarter goal from Shea McAleese gave the Black Sticks their first lead of the night, which they carried en route to a 4-1 victory in Mt Maunganui.
The win meant that Black Sticks were the last unbeaten team in the competition after Belgium beat India earlier in the day.
The Kiwi side went into the match with the favourites tag, ranked seven spots higher than Japan (16) in the world. However it was Japan who had the better start, stifling the Black Sticks' attack and working hard on the counter.
The New Zealand side were stunned in the first quarter when a fast attack from Japan saw them get onto the score sheet to lead 1-0.
It was a slow start for the Kiwi side as they looked to be trying to force plays when they had the ball.
They came in more composed in the second quarter and were rewarded just before the half-time break when George Muir got the last touch on a penalty corner to level things at 1-1.
The plan didn't change for Japan in the second half as they appeared content to defend for as long as required and try catch New Zealand off guard with counter attacks.
However, a reckless challenge midway through the period saw them lose a man to a yellow card and the Blacks Sticks made Japan pay.
The hosts went up through McAleese who, after a penalty corner play, was able to tap in from close range.
The Black Sticks added to their scoreline through Arun Panchia and Kane Russell, who also scored from penalty corners, to put the match beyond any doubt.
The sides get a day off now, before the Black Sticks play India and Japan face Belgium on Saturday.