Kim Sei-young and Danielle Kang both blitzed their second rounds to earn a share of the 36-hole lead at the Women's PGA Championship.
South Korean Kim and American Kang carded five-under-par 66s on Friday to be one-shot clear at Olympia Fields in Illinois.
Kim - the 2015 LPGA Rookie of the Year - had six birdies and a bogey, while Kang - the Women's Amateur champion in 2010 and 2011 - was flawless as she recorded five birdies without a blemish.
"Both of those rounds, I kept my game plan, and they were both bogey-free, so I'm pretty happy," Kang said. "I kept sticking to the iron shots that I trusted all my life, and giving myself opportunities is what weve been doing."
The pair are seven under overall at the halfway stage of the major tournament, ahead of Brittany Lincicome (66), Jodi Ewart Shadoff (66), Lee Mi-hyang (67), Chella Choi (70) and Amy Yang (71).
Choi and Yang were the overnight leaders but they were unable to stay atop the leaderboard.
After opening with a 66, Choi could not stay in the 60s, while Yang returned to complete her first round - a 65 - after dangerous weather suspended play on Thursday.
Defending champion Brooke Henderson is two shots off the pace following her two-under-par 69.
The Canadian is tied for eighth alongside three others, while she is a stroke clear of Lydia Ko (68) and Michelle Wie (70).