American Brittany Lincicome surged to a three-stroke lead after the second round at the LPGA Championship following a four-under-par 68 at the Monroe Golf Club in Pittsford, New York.
Lincicome, a five-time LPGA Tour winner, was at nine-under 135, while compatriot Lexi Thompson (72) and South Korean Park Inbee (66) were equal second on six-under.
Thompson was the first round leader, while Park is defending champion.
Lincicome and Thompson are both long hitters, and the halfway leader is not surprised they are running first and equal second.
"There is no secret why Lexi and I are at the top of the leaderboard, both long hitters taking advantage of the par-fives," Lincicome told reporters. "The more I can hit driver, the better, so we go to a golf course and it takes driver out of my hand, I'm pretty bummed. Here, I'm excited."
New Zealand teenager Lydia Ko shot 69 to stay in the hunt, four strokes behind as she seeks to become the youngest major winner, while world number one Stacy Lewis was nine strokes off the pace after a 73.