"I haven't played well here," she said. "What gives me more confidence than anything is that I was able to still get up there and hit some good shots. I've been playing well all year, so it's fun to be out there just playing and not working on your golf swing or your stroke or anything. It's just nice to play golf."
Helped by an eagle at the par-5 third and birdies on her final two holes, Lewis moved into a tie with Miyazato, who teed off in the first group of the day off No. 1 and got off to a great start with a bogey-free round.
Former U.S. Women's Open champion Paula Creamer, who also has tweaked her swing for the better, eagled the 18th to finish with a 67, where she was tied with Colombia's Mariajo Uribe. Maude-Aimee Leblanc of Canada was at 68, one shot ahead of a seven-player group that included 17-year-old Lexi Thompson.
Lewis, whose battle with scoliosis has made her a role model for young girls, went through an interesting three-hole stretch in a round that began in bright sunshine and near-calm conditions and finished in clouds and a good breeze.
After sinking a 25-foot birdie putt on the first hole, her 10th of the round, Lewis flew the green at the tough par-4 second, chipped on, and 3-putted for double bogey. But with No. 3, a short par 5, playing downwind, she hit a 6-iron from 195 yards out to within six feet and sank the eagle putt.
"Certain tee shots I get up on, and just the way the wind's blowing, it's just hard for me to line up and really trust it," said Lewis, who finished with six birdies. "So it helps that I'm playing well and that I'm trusting my golf swing.
"I came in here last year and wasn't trusting my golf swing. You're not trusting where you're lined up and then you're not trusting where the ball is going to go. That's usually not a good combination. So I think just knowing that I'm playing well has helped the golf course fit me a little more."
Seeking her first LPGA victory, Miyazato, 22, carded her first eagle of the season at the par-5 ninth hole, where she sank a 20-foot putt, to spark her round. She almost holed out her tee shot at the short 17th and birdied there.
Creamer, 25, whose only LPGA top 10 this season came in an unofficial event, saw a good day get better at the last hole. With 235 yards to the par-5 hole, she cracked a 3-wood "and grinded out a good six-footer for eagle, and it was nice," she said.
During an off-week last week, Creamer said, she worked on her swing, and it showed Friday in the result.
"We did a lot of video work and something just really clicked," she said.
Shore notes. Amateur Meghan Stasi, who is originally from Voorhees, bogeyed her last two holes and finished with a 75. . . . Yani Tseng, the world's top-ranked player, carded a par 71.
Contact Joe Juliano at 215-854-4494 or jjuliano@phillynews.com, or follow him on Twitter @joejulesinq