"The wind was quite surprising because we were playing in the morning and expected it to be pretty still," said Ko. "I think it's a pretty solid score in this wind."
Fellow New Zealander Cathryn Bristow, who secured her Ladies European Tour (LET) card at the end of 2012, also carded a two under par 70 in the afternoon field to be in contention.
Followed by the largest gallery on course in the morning field, Ko made five birdies and three bogeys. It was an up and down start to her charge to become the first New Zealand winner of the event.
She was at her ball-striking best but her putter at times went as cold as the wind and conditions at Clearwater. "I had a few lip-outs and stuff like that which kind of made me more angry. To me, if it didn't go in, I'd rather it didn't even go near the hole, but lip-outs ... for it being so close, that gets me more annoyed."
Ko missed short putts for par on holes one and 12 but there were some good ones too - like the birdies on three and eight from around 3m and the scrambling par on the 15th.
"I needed that putt [on 15] in the wind so in those kinds of areas it was good, but in the areas where I did leave some out it wasn't so great. [My putting] was pretty much in the middle."
Ko, who has played Clearwater around 16 times in the past eight days to make a strong challenge for the title, admitted to feeling the nerves on the first tee as the local hope.
"I was a little nervous, but then it kind of died away after the first couple of holes." While Ko was content enough with her start her world-class rivals had forgettable rounds in the wind.
Swedish major champions Sophie Gustafson and Anna Nordqvist had rounds of 78 and 79 respectively and the highest ranked player in the field, World No 19 Angela Stanford, was off the pace after signing for a 78.
The 2009 champion Gwladys Nocera (73) was the best of the former winners as Laura Davies (74), and Kristie Smith (75) were slow out of the blocks in the 54-hole event.
Ko will have to battle the prevailing nor' easterly wind tomorrow afternoon as she looks to keep her perfect record of never missing the cut in professional tournaments alive.
Remarkably Ko in the 11 pro events she has played has; won twice, finished runner-up twice and finished as the low amateur in two major championships.
It is little wonder that Ko is the World No 38 and the third-ranked player in the field this week.
She said she hoped her putting would help her go low in round two.