GALLOWAY, June 1, 2014 (AFP) - Battling gusty conditions, Lewis finished 36 holes at 12-under-par 130 and the American put herself in position for a victory that would move her past South Korea's Park In-Bee for the top ranking spot.
Lewis will go for her 10th LPGA title and second victory of the year on Sunday at the Stockton Seaview Hotel and Golf Club.
Lewis said all she needed to do Saturday was tweak some aspects of her game to get in the right frame and that translated into better scores.
"I know my tendencies," she said. "I had to just get comfortable."
Christina Kim, ranked 104th in the world, posted a four-under 67 and moved into second place at 131.
Jennifer Johnson, who matched the course record Friday with a 62, shot 70 and ended two rounds at 10-under 132.
Anna Nordqvist (65) and Gerina Piller (67) shared fourth place at eight under, while Kang Hae-ji (67) is alone in sixth at 135.
Lewis, who tied the 36-hole course and tournament record, won this tournament two years ago in 2012 and would become the fourth woman to win the event more than once.
She hopes to join Juli Inkster (1986, 1988), Betsy King (1987, 1995, 2001) and Annika Sorenstam (1998, 2002) as those who have won the event twice.
"The first nine holes yesterday I just was uncomfortable over the ball," said Lewis. "I got off to a better start. My alignment was kind of messed up the last few rounds, and I started to figure it out throughout the day yesterday, and it definitely felt a lot better today.
"I hit the ball a lot more solid and didn't have to make as many par putts. It was just a lot easier overall."
Lewis said she made some adjustments on her alignment and it ended up making a difference.
"My tendencies are for my feet to get closed," she said. "I do it all the time and you wish you could figure out some way to not do it. That's the tendency.
"My feet at the moment feel pretty open which is hard because I feel like I'm going to hook the ball."
Kim kept herself in contention with five birdies and a bogey in the second round. She has not won on the tour in almost a decade.
"The scores are finally starting to add up," said Kim. "It has just been a work in progress and I've just been steadily waiting patiently for things to start falling into place."
Leading scores after Saturday's second round of the ShopRite LPGA Classic (USA unless noted, par-71):
130 - Stacy Lewis 67-63
131 - Christina Kim 64-67
132 - Jennifer Johnson 62-70
134 - Anna Nordqvist (SWE) 69-65, Gerina Piller 67-67
135 - Haeji Kang (KOR) 68-67
136 - Inbee Park (KOR) 66-70, Haru Nomura (JPN) 63-73
137 - Na Yeon Choi (KOR) 66-71, Julieta Granada (PAR) 71-66, Dori Carter 69-68, Kim Kaufman 69-68, Brittany Lincicome 67-70
138 - Lindsey Wright (AUS) 68-70, Sandra Gal (GER) 67-71, Chella Choi (KOR) 67-71, Amy Anderson 70-68, Mi Hyang Lee (KOR) 68-70
139 - Laura Diaz 67-72, Becky Morgan (GBR) 69-70, Karrie Webb (AUS) 69-70, Michelle Wie 67-72, Brittany Lang 69-70, Sydnee Michaels 68-71, Mariajo Uribe (COL) 70-69, Sarah Kemp (AUS) 67-72, Shanshan Feng (CHN) 74-65, Christel Boeljon (FRA) 71-68, Kelly Tan (MAL) 69-70