"Korea were a team we needed to beat, they are ranked below us so we needed to take three points from them and we did well to do that today."
Defender Stacey Michelsen said her side's ability to move the ball around the field in hot conditions proved the difference.
"Our linking through the layers all across the turf was great today, we really played as a team which was fantastic.
"It's always very important to be able to keep moving the ball around in the heat, and we certainly did that well and it led to goals."
New Zealand made a strong start to the match and had Korea under plenty of pressure in their defensive half thanks to a dominant midfield.
Striker Kirsten Pearce opened the scoring in the ninth minute after a quick-fire finish in traffic from close range.
New Zealand doubled the advantage 10 minutes later when Charlotte Harrison put her body on the line with a magnificent diving reverse shot which soared past the goalkeeper's pads.
It was the Kiwis again in the 20th minute as a perfect execution of a penalty corner set piece saw Anita McLaren fire wide to Gemma Flynn for a deflection into goal.
Leading 3-0 at halftime, it took just three minutes in the third quarter for another goal with Petrea Webster connecting with Kayla Whitelock's ball into the circle to send an amazing diving deflection past the keeper.
Hyunji Kim scored a consolation goal for Korea with just six minutes remaining in the match.