"The girls prepared well for this after the game was postponed and we came out today ready to play," Harrison said post-match.
"Our basics at times still let us down today so we need to fine tune those, stick to our structure and play as a team against Great Britain."
The Black Sticks looked strong from the opening whistle and opened the scoring in the 19th minute thanks to a brilliant solo effort from Harrison, who ran the ball up the field and smashed home from the top of the circle.
Leading by one goal at halftime, New Zealand turned up the heat in the third quarter and extended the lead two minutes after the break when Pippa Hayward found herself open for a strong shot past the goalkeeper.
Liz Thompson gave the Kiwis a three goal buffer 10 minutes later with a penalty corner flick which snuck through the keeper's feet.
Germany got onto the scoreboard just out from three quarter time with a goal to captain Franzisca Hauke from a penalty corner.
The Black Sticks held strong under pressure in defence throughout the fourth quarter while still managing to create chances in the attacking circle.
BLACK STICKS 3: (Charlotte Harrison, Pippa Hayward, Liz Thompson)
GERMANY 1: (Franzisca Hauke)
Halftime: New Zealand 1-0