The Black Sticks progressed to a playoff for fifth and sixth place with Spain this morning.
After a heart breaking loss to Canada in Friday's quarterfinal, the Black Sticks were pleased to rebound.
''I thought we overcame the anguish of the quarterfinal and did what we needed to,'' coach Colin Batch said.
''We had some good meetings following that game and players responded really positively. I think full credit needs to go to them for coming out and playing well today.
''We had good control of the game, particularly in the first half, although it would have been nice to have had a second goal before the break.
''The third quarter was better and then I thought we had some difficulty in the fourth quarter, but in the end we got there.''
The Black Sticks had 19 circle penetrations, leading to 18 shots, highlighting their dominance up front.
They came out firing, maintaining an 80% possession rate and creating opportunities that often caught Japan off guard.
The reward came early in the second quarter when Stephen Jenness dribbled along the baseline and, with defenders all around him, found just enough space to slide it into the goal.
Japan worked hard in the second spell, holding more possession and territory, but the Black Sticks defenders rallied well when required.
The second goal came immediately after halftime. The Black Sticks were awarded a penalty stroke and Shea McAleese stepped forward and confidently slotted it high over the keeper's pad.
Throughout the game, the New Zealanders were awarded six penalty corners, but some botched traps and good defence from Japan's goalkeeper prevented them from converting until the 49th minute, when Andy Hayward stretched it to 3-0.
Genki Mitani pegged one back for Japan in the 58th minute, but the Black Sticks had the last say when captain Simon Child set up Steve Edwards, who was perfectly positioned in front of the posts to score a fourth.
The New Zealand women's team was beaten 2-0 by the Netherlands in the second of two tests at the Noordwijkse Hockey Club in Holland yesterday.
The world champion Dutch had the majority of possession in the first quarter but could not find a way through the New Zealand defence as goalkeeper Sally Rutherford made some top saves.
Both sides had several scoring chances in the second quarter but only the Netherlands capitalised with some clever rebounding off an initial save.
Striker Kirsten Pearce was unlucky not to score the equaliser through a stinging shot at goal just deflected wide by the Dutch keeper.
Leading 1-0 at halftime, the Dutch turned up the pressure in the third quarter and extended their lead with a sharp shot from the top of the circle following a quick long corner.
New Zealand pushed hard to pull a goal back but was unable to get the ball into the attacking circle.
World League
The scores
New Zealand 4
Stephen Jenness, Shea McAleese, Andy Hayward, Steve Edwards
Japan 1
Genki Mitani
Halftime: New Zealand 1-0
