PITTSFORD, August 16, 2014 (AFP) - The American, whose resume includes a major title at the 2009 Kraft Nabisco Championship, had a 36-hole total of nine-under-par 135.
She was in good shape to make a weekend run at a fifth tour title, and her first since the 2011 Canadian Women's Open.
American Lexi Thompson, the reigning Kraft Nabisco champion who shared the first-round lead with South Korea's Meena Lee, carded an even-par 72 and shared second place on 138 with defending champion and former world number one Park In-Bee.
South Korea's Park climbed up the leaderboard with a six-under 66.
New Zealand teen Lydia Ko, who could seize the world number one ranking from Stacy Lewis with a first major win this week, carded a 69 to head a group tied on 139.
She was joined by overnight co-leader Lee, who signed for a 73, and American Jane Park, who posted a 69 at Monroe Golf Club.
Half a dozen players were tied on 140. They included 2007 champion Suzann Pettersen of Norway, who shot 69, and 2012 winner Feng Shanshan of China, who signed for a 72.
They were joined by South Korea's Lee Mi-Rim (71), Paraguay's Julieta Granada (65), Spain's Beatriz Recari (70) and American Jennifer Johnson (70).
Leading second-round scores on Friday in the LPGA Championship at Pittsford, New York (USA unless noted, par-72):
135 - Brittany Lincicome 67-68
138 - Park In-Bee (KOR) 72-66, Lexi Thompson 66-72
139 - Jane Park 70-69, Lydia Ko (NZL) 70-69, Meena Lee (KOR) 66-73
140 - Julieta Granada 75-65, Suzann Pettersen (NOR) 71-69, Jennifer Johnson 70-70, Beatriz Recari (ESP) 70-70, Lee Mi-Rim (KOR) 69-71, Feng Shanshan (CHN) 68-72
141 - Gerina Piller 72-69, Azahara Munoz (ESP) 71-70, Paula Reto (RSA) 70-71
142 - Choi Na-Yeon (KOR) 74-68, Mo Martin 72-70, Kristy McPherson 71-71, Tiffany Joh 70-72, Lee Il-Hee (KOR) 69-73, Ji Eun-Hee (KOR) 69-73, Anna Nordqvist (SWE) 69-73, Cristie Kerr 68-74, Lisa McCloskey (COL) 67-75
143 - Sydnee Michaels 74-69, Laura Diaz 73-70, Thidapa Suwannapura (THA) 72-71, Laura Davies (ENG) 71-72, Sarah Kemp (AUS) 71-72, Lin Xiyu (CHN) 71-72, Jessica Korda 70-73, Danielle Kang 70-73