Kim sets the pace at LPGA Match Play after early birdie binge
The 31-year-old South Korean has not won an LPGA title since the November 2020 Pelican Championship, which came a month after her lone major win at the Women's PGA Championship.
A revamped format for this year's event at Shadow Creek in Las Vegas features three rounds of stroke play with the top eight advancing to weekend match play.
Kim, ranked 39th, opened with a birdie, added another at the third hole and reeled off three in a row ending at the par-3 eighth.
She birdied to begin the back nine and answered her lone bogey at 14 with a birdie at the par-5 16th.
"It's a change, the format (of) first three rounds, and feels like a lot of things going on," Kim said.
"It works today. The front nine I didn't expect I would play... this well. I was just like, some holes, par is best, so I kind of play very smart. That's what I wanted to do, so pretty solid round. I'm very happy with that."
Kim, who won her first of 12 career LPGA titles in 2015, has adopted a more cautious tone with her game rather than attacking the pins.
"But now I don't follow anymore because if you follow the hole it can be the water, so just kind of very safely play this week."
Rose Zhang, who began on the back nine, birdied her last four holes to seize a share of second with fellow American Danielle Kang on 67.
"I felt like I was just really patient out there," Zhang said. "I had a really good game plan coming in. You can't really go at pins on this golf course, so making sure that I have my targets and iron play was pretty exceptional. I really gave myself many opportunities out there."
Zhang, 20, won her pro debut last June at the LPGA Americas Open, the first player to win her pro debut at an LPGA event since Beverly Hanson in 1951.
Kang, who also started off the 10th tee, birdied four of her last seven holes to finish on 67.
"I played well. I had some really good putts," Kang said. "I executed really good shots, prepared well. I get to be home this week, so I'm really happy to be here."
Sharing fourth on 69 were Japan's Yuka Saso, Australian Minjee Lee and Sweden's Anna Nordvist.