Midway through the third quarter the Kiwis took their first lead of the match when Shea McAleese got the final touch on a penalty corner shot.
The Black Sticks pulled further ahead from a 49th minute penalty corner with Nic Woods executing the perfect drag fake for Arun Panchia to smash a forehand shot into the backboard.
Kane Russell iced a convincing performance with a rocketing drag flick with just three minutes remaining on the clock.
Head coach Darren Smith was pleased with the performance against a determined Japan side who battled until the final whistle.
"Japan came out of the blocks very well and showed some firepower which threw us off a little bit," he said.
"We made it tough for ourselves early on but in the second quarter things started to change and the second half was pleasing. It's great to put together our second win in a row against high quality teams.
"We're looking forward to our next match against India on Saturday. They're quick, skilful and have a great corner so it will be a good challenge for us."
Earlier in the evening, Belgium powered to their first win of the series with a 2-0 result over India thanks to goals from Arthur de Sloover and Victor Wegnez.
Teams have a rest day tomorrow before getting back in action on Saturday with the Vantage Black Sticks facing off against India at 12.15pm and Belgium taking on Japan at 2pm.
Both tests will be streamed live and then available on demand through the Vantage Black Sticks Facebook page.
Day two results - Blake Park, Tauranga
Vantage Black Sticks: 4 (George Muir, Shea McAleese, Arun Panchia, Kane Russell)
Japan: 1 (Kenta Tanaka)
Halftime: 1-1
Belgium: 2 (Arthur de Sloover, Victor Wegnez)
India: 0
Halftime: Belgium 1-0
