"My goal was four under today, and I shot four under on the back nine which is good once again," Ko said. "And I did that yesterday as well.
"I think I really like the back nine, and hopefully it likes me, too."
Ko is playing in only her 10th professional event and third tournament on the LPGA Tour after the Australian and US Open. She is playing among many of the top players in the world and looking to become the first Kiwi golfer to win on the LPGA Tour.
"It's nerve-racking playing with the pros and actually playing against the pros," she admitted. "I'm really here for experience, and it's awesome to see what the pros can do.
"I am actually playing pretty good. I kind of lost confidence after my front nine. But my birdies on 12, 13 and 14 just made me go way up there.
"The only time I really looked at the leaderboard was on 15. Suddenly people with cameras were coming and I was like, 'are they actually going to take footage of me?' And I was like, 'oh, man'. I took a peak at the leaderboard and my name was at the top. It was like, 'oh, my God'."
Ko wowed the international media with her composure at the post-round press conference as she was quizzed on her plans to go to Stanford University and turn professional, what it's like playing with her idols like Michelle Wie and Lexi Thompson and how she finds time to fit in her schoolwork.
Ko believes she can win the Canadian Open. She took a lot of confidence from her win at the NSW Open - where she became the youngest winner of a professional golf event - and her performance in her major debut.
"At the US Open I shot 3-under 'til 15. That showed I was able to handle it along with the pros. That kind of gives me confidence. But New South Wales Open was a European Tour event, and the win helped me and gave me confidence that I could beat the pros. You never know what's going to win."