"Nice to kind of have that ball striking. Obviously takes a little bit of pressure off the short game. Overall I played really solid."
Ko was pleased to put everything together after her first two rounds had some blemishes.
"I made some kind of careless mistakes the first couple rounds. I felt like some of the bogeys I made were probably not necessary. It wasn't like I was out of position or in that bad of a lie, I would just three-putt, miss a short one.
"Over the last few weeks I felt like I made some kind of silly mistakes, so I'm trying to do a better job with that. Even if I do have like a three- to six-footer for par, not get to stressed out about it and just be committed."
She'll need to back it up again tomorrow chasing some big names.
It's a stacked leaderboard, all of the top five are major winners, with world No 2 Korda a shot ahead of fellow American and ANA Inspiration winner Jennifer Kupcho.
Ko shares fifth with world No 3 Minjee Lee, while defending champion Korda made a 22-foot eagle putt on the par five 18th to take the outright lead into the final round.
Making her second start since returning from a four-month break because of a blood clot in her left arm, Korda also eagled the par five eighth and had three birdies and a bogey at Blythefield Country Club.
"I'm just happy to be out there playing again," Korda said. "I'm in contention, but I've been in this position before. Thankfully, I can lean on that."
Kupcho, two strokes ahead of playing partner Korda entering the day, had a 69 to drop a shot back. She rebounded from her first bogey of the week — on the par-four 17th — with a two-putt birdie on 18.
"I wasn't playing as well as I thought I should," Kupcho said. "I think after a little bit of a rough start, missed a couple fairways, I kind of set a goal for myself to shoot three-under and I did do that. So glad to have done that."
The second-ranked Korda tied for eighth two weeks ago in the US Open in her first event since early February. She also is the defending champion next week in the Women's PGA at Congressional.
"I knew that I had enough practice under my belt and it was just more of like, 'Can I put that into tournament golf,'" Korda said. "So far, I've played pretty well and hopefully I can continue."
Kupcho won the major tournament at Mission Hills in the California desert in early April for her first LPGA Tour victory.
"The whole top of the leaderboard are all good players," Kupcho said. "Anything can happen. Anything can happen on the back nine. There is a couple reachable par fives."
Brooke Henderson, the ShopRite LPGA Classic winner last week in New Jersey and 2017 and 2019 champion at Blythefield, was third at 15-under after a 67.
Lexi Thompson, the 2015 winner, had a 68 to get to 14-under.
"I play this golf course pretty aggressively," Thompson said." Hit a lot of drivers, take a lot of corners on. So, probably not play any more aggressively, except maybe fire at a few more pins. All depends on pin locations, too. Play the same way I have been and maybe roll a few putts."
Following the six major champions, Atthaya Thitikul (67) and Madelene Sagstrom (70) were tied for seventh at 12-under.