Ryu fires another 64 to lead LPGA NW Arkansas Championship
The world number 37 stood on 14-under 128 after 36 holes in the 54-hole event at Pinnacle Country Club in Rogers, Arkansas.
"I can't hit a bogey these two rounds and I'm so happy," Ryu said. "This week my shot is so perfect.
"I think it's the first time I hit a 60-score (twice) in a row and I want to try one more round."
Japanese rookie Yuna Nishimura (23) also fired a 64 to share second on 130 with Australian Hannah Green (26). South Korea's Jenny Shin (30) was third on 131 with compatriot Kim Sei-Young another stroke adrift.
Ryu, a five-time winner on the Korean LPGA tour and LPGA Q-school medalist, has five top-10 finishes this year, including eighth at the US Women's Open at Pebble Beach.
She birdied the par-3 11th hole and added another at the par-5 18th to close her first nine, then reeled off four consecutive birdies from the par-3 third through the par-3 sixth holes and concluded her round with a birdie at the par-4 ninth.
"Today on the first nine holes my shot is so perfect but I can't make birdie, I can't focus on my putts. Always I miss the cup," Ryu said. "First nine holes my putt is going off to the right."
But the rookie revived her form after her birdie at 18.
"OK, I have more chance and I have more holes left," Ryu told herself."Yeah, it was more confidence after nine holes that I can make so many birdies, and I got it."
Nishimura started on the back nine and birdied four of her first five holes then birdied four of the first six on her second nine before a bogey at the eighth dropped her two off the pace.
Nishimura's only top-15 result in 22 prior LPGA starts was a fourth-place showing in last year's Japan Classic.
World number 24 Green, the 2019 Women's PGA Championship winner, captured her third LPGA title in April at the LA Championship.
The Perth native closed with back-to-back birdies to shoot a bogey-free 65.
"Really happy with today's round because it felt kind of flat through the middle there, and then it was nice to pick up two birdies the last two holes," Green said.
Shin, ranked 72nd, began on the back nine and opened with five birdies in her first six holes, but stumbled with a bogey at the first. Shin answered with a birdie at the fourth and closed with five pars.
Shin, from Seoul, won her only LPGA title at the 2016 Texas Shootout. Her best showing this year was sixth at another 54-hole event, the ShopRite Classic in June.
