Lin Xiyu of China fired an eight-under-par 64 to seize a one-stroke lead over Japan's Nasa Hataoka after Thursday's first round of the LPGA Queen City Championship.
The 26-year-old from Guangzhou made nine birdies against a lone bogey to finish one off her lowest LPGA round and pace the field after 18 holes at Kenwood Country Club in Cincinnati, Ohio.
"I'm happy with how I'm playing right now," Lin said. "My confidence is pretty high, really up there."
Australian Sarah Kemp and South Korean Kim A-lim shared third on 66 with a pack on 67 including Thailand's Moriya Jutanugarn, Atthaya Thitikul and Jasmine Suwannapura, South Koreans Choi Hye-jin and Kim Sei-young and American Katherine Perry-Hamski.
Lin, who shared seventh last week, seeks her first LPGA title and had her best tour finish in March at Thailand, when she lost a playoff to Denmark's Nanna Koerstz Madsen.
Lin, making her 188th career LPGA start, hasn't missed a cut this year and took full advantage of softened conditions after five inches of rain in five days.
"Overall, I'm really lucky we got to play," she said. "With that much rain, the greens were rolling really well and I was putting really well."
Lin began on the back nine with three birdies in a row, added two more at the par-3 14th and par-5 15th and another at the 18th hole.
She had back-to-back birdies again at the par-3 third and par-5 fourth before stumbling with a bogey at the seventh.
Lin answered with a 15-foot birdie putt at the par-3 eighth to reclaim the solo lead before a closing par.
Hataoka, 23, chases a seventh career LPGA title, having won her most recent crown in April at the Los Angeles Open.
Hataoka birdied the fourth, seventh and ninth holes, then added birdies at 11 and 12 before her lone bogey at 13, which she followed with birdies on the next three holes.
"I was able to make good birdie chances and my putting was good," Hataoka said. "I only had one bad tee shot. My shots really got to the pins so I was able to get the birdies.
"My distance control was really good. I managed the course really well."
Paula Creamer, an American whose 10 LPGA triumphs include the 2010 US Women's Open, made a hole-in-one at the par-3 eighth, dropping in a 7-iron from 155 yards.
She also holed out for eagle from 104 yards using a 52-degree wedge at the par-4 fifth in shooting 72.