Lewis, bidding for a third major title, birdied the 14th, 16th and the eighth after starting her round at the par-five 10th to finish two strokes in front of Australian Katherine Kirk and South Korea’s Ryu So-yeon.
Veteran Australian Karrie Webb, who won the 2001 U.S. Women’s Open played at nearby Southern Pines, opened with a 70 while reigning champion Park Inbee of South Korea made a faltering start to her title defence, carding a 76.
Lewis, who clinched her first major title at the 2011 Kraft Nabisco Championship, was delighted with her form on a firm and fast-running course where only three players finished under par after last week’s men’s U.S. Open.
“I’m very happy,” the 29-year-old from Ohio told reporters after taking control of the year’s second women’s major. “It was such an easy day. I played really, really solid.
“I didn’t put myself in too bad of spots and made a few birdies, which was nice. I had a lot of tap-in pars. I wasn’t struggling to make par all day.
“I was really hitting the shots I needed to hit. I was in control of how far I was hitting it. So that’s what made it easy. The golf course wasn’t easy, by any means. It’s going to play hard the rest of the week.”
Lewis won her second major crown at last year’s Women’s British Open and has made the grand slam events her number one priority.
“Everything I’m doing is geared towards majors,” said the American, whose best U.S. Women’s Open finish was a tie for third in 2008. “You have to have control of the ball, you have to putt great and you have to have control of your emotions.
“The last one, that’s been the kicker for me the last few years … and I did a really good job of that today.”
While Lewis flourished in Thursday’s opening round, Korean Park struggled on her way to a 76 that included four bogeys and two doubles.
“Just a combination of everything,” said the 25-year-old, a four-times major champion who at 19 became the youngest ever winner of the U.S. Women’s Open with a four-shot victory in the 2008 edition at Interlachen Country Club.
“A couple of really important par putts just missed the hole, some lip-outs and it just was not a nice day. On this golf course you make a couple of mistakes, you can easily shoot a high number.”
Park, who won last year’s U.S. Women’s Open at Sebonack Golf Club in New York to become only the second LPGA player to win the first three majors in a season, has lowered her sights for Friday’s second round.
“My plan will be making less bogeys tomorrow and trying to just stay out of the trouble, not so much about the trophy now any more,” the Korean said.
American Lucy Li, who at the tender age of 11 became the youngest ever to qualify for the U.S. Women’s Open in her sectional qualifier last month, opened with an eight-over 78.
“It was a lot of fun,” said the ever-smiling Californian, her hair in pig-tails and a popsicle in one hand as she spoke to reporters after her round. “I kind of struggled, but it was great.
“I’m happy I broke 80, because I got two doubles and a triple and that can really ruin a score. I just need to get rid of the big numbers.”
Asked what her plans were for the rest of the day, Li replied with a grin: “Eat some more ice cream.”
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Frank Pingue)