Coach Mark Hager had urged his troops to "make good decisions" in the second half but they were mostly unable to retain possession and had few clear cut chances.
In oppressive, sweltering heat New Zealand made a tentative start and Korea could have scored twice in the first six minutes but failed to capitalise on good chances.
The Black Sticks made them pay four minutes later with a well constructed goal. Charlotte Harrison split the Korean up the middle, before releasing Katie Glynn. The midfielder showed good composure to find Catherine Finlayson, who forced the ball home on the second attempt.
It meant New Zealand, together with the Netherlands, are the only teams to score the opening goal in both of their matches so far.
The first half was end to end and the game very spread; not ideal in the conditions, with the temperature over 35 degrees celcius and extreme humidity. The Black Sticks did not help themselves with several needless turnovers in the middle of the park, though you could not fault the effort.
Chances continued to flow with good opportunities to Gemma Flynn, Glynn and Sam Charlton while Korea somehow contrived to waste a golden two on one opportunity.
New Zealand then had three consecutive penalty corner chances but could not find a clean strike. They were clearly disappointed but doubled their lead soon afterwards in the 25th minute.
After an incisive dribble by Charlotte Harrison she found Glynn, who smashed a backhand shot into the corner - her sixth Champions Trophy goal, with the last three coming against the Koreans.
Just before the half Bianca Russell, who had an excellent match in the New Zealand goal, defused successive penalty corners.
The second stanza was a nailbiter. Korea scored from their fifth penalty corner of the match to guarantee a grandstand finish.
At times they were under siege but the defence held strong; at one stage the ball were virtually over the line, before Stacey Michelsen defied the laws of physics to extract the ball from the New Zealand goal.
There was an element of luck in the Korean equaliser - with the ball appearing to loop off an outstretched stick and over the stranded Russell - but it was no more than the Asian side deserved after periods of extended dominance in the second half.
In today's other matches, Great Britain held the fancied Netherlands side to a 2-2 draw while China picked up their first win of the tournament at the expense of the other Asian nation, beating Japan 2-1, though the Japanese had the consolation of scoring their first goal.
New Zealand's next match is against Germany on Wednesday (NZT).
* Herald on Sunday writer Michael Burgess travelled to Argentina with assistance from Hockey NZ.
