Lewis had a nine-under par total of 135, one stroke in front of four players sharing second
American Stacy Lewis birdied five holes on the back nine on Friday en route to a five-under 67 that gave her a one-shot lead in the Mobile Bay LPGA Classic.
Lewis, who won the Kraft Nabisco championship last year, arrived at the 18th with a two-shot lead after making three birdies in a row, but she missed a five-footer for par.
Despite the blemish, she had a nine-under par total of 135, one stroke in front of four players sharing second on 136.
Lewis's effort was a welcome contrast to her performance at the Lotte Championship in Hawaii last week, where she missed the cut.
"It was really one of those weeks," she said. "I had a lot of stuff going on. Mentally I was kind of not there. I'm a lot more relaxed this week. I just kind of chalked one up to a bad couple of days, and I'm just kind of moving on."
Sweden's Karin Sjodin fired a course record-equalling 64 on The Crossings layout to join the group at eight-under, which also included South Korea's US Open champion So Yeon Ryu (67), Sydnee Michaels (68) and Australian Lindsey Wright (69).
Sjodin's best finish on the LPGA tour is a fourth-placed tie at the Kraft Nabisco championship earlier this month.
France's Karine Icher and South Korean Chella Choi both posted 65s to join a group on seven-under 137 that also included Brittany Lincicome, South Korean Sun Young Yoo and Colombia's Mariajo Uribe.
Lewis said her score owed more to consistency than anything spectacular, although she did roll in a 20-footer for birdie at 17.
"It's really just been boring golf," she said. "I haven't made a ton of putts. I've just hit a lot of shots close and taken advantage of the par fives. It's been pretty relaxing."
Wright, playing in the one of the late groups, pulled within a shot of the lead but couldn't find a birdie in her last 11 holes.
"Playing in the second-to-last group, it was a little bit difficult to read putts and make putts," said Wright, who won the New Zealand Women's Open in February.
"I think I hit it just as good on this (final) nine. It's disappointing not to birdie anything, but I'm in a great spot coming into the weekend."
Wright, who teed off on 10, finished with three birdies and no bogeys.
"I'm one shot from the lead. No pressure, really," she said.
Three players who shared the overnight lead with Wright faded. Jennifer Rosales carded an even-par 72 that left her four shots adrift, while Sweden's Caroline Hedwall signed for a 73 and Katie Futcher a 77.