GALLOWAY, 31 May 2015 (AFP) - The 27-year-old US standout stood on seven-under 135 through 36 holes at the 54-hole event, one stroke ahead of Sweden's Anna Nordqvist as she pressed for her first victory since the 2008 Kapalua Classic.
Pressel's only other triumph came in 2007 when she won her first major title at the Kraft Nabisco Championship.
But Pressel has improved this season, settling for second at the Swinging Skirts LPGA Classic last month at San Francisco, losing to New Zealand teen star Lydia Ko in a playoff.
Pressel birdied the par-5 third and par-4 sixth, took her lone bogey of the day at 13 but answered with a birdie at 16.
Nordqvist also shot 69 to stay one stroke off the pace. She also birdied the third, but endured back-to-back bogeys at 11 and 12 before closing with birdies at 16, the par-3 17th and the par-5 18th to stay on Pressel's heels.
It was another two strokes back to a third-place pack on 138 that included Dutchwoman Christel Boeljon, Scotland's Catriona Matthew, Sweden's Pernilla Lindberg and Americans Gerina Piller and Kelly Shon.
South Korean Yoo Sun-Young and Americans Kim Kaufman and Marissa Steen shared eighth on 139.
Leading scores after Saturday's second round of the Shoprite LPGA Classic (USA unless noted, par 71):
135 - Morgan Pressel 66-69
136 - Anna Nordqvist (SWE) 67-69
138 - Catriona Matthew (SCO) 68-70, Pernilla Lindberg (SWE) 68-70, Kelly Shon 70-68, Gerina Piller 68-70, Christel Boeljon (NED) 68-70
139 - Marissa Steen 69-70, Kim Kaufman 69-70, Yoo Sun-Young 69-70
140 - Jaye Marie Green 73-67, Ayako Uehara (JPN) 72-68, Paula Creamer 72-68, Oh Ji-Young (KOR) 71-69, Felicity Johnson (ENG) 70-70, Feng Shanshan (CHN) 70-70, Mirim Lee (KOR) 70-70, Mika Miyazato (JPN) 69-71, Moriya Jutanugarn (THA) 69-71, Ryann O'Toole 67-73
141 - IK Kim 73-68, Ai Miyazato (JPN) 71-70, Park In-Bee (KOR) 71-70, Min Lee (KOR) 67-74, Mariajo Uribe (COL) 70-71, Mo Martin 69-72