PHOENIX (AP) -- When told she could take the No. 1 spot in the world with a victory at Desert Ridge, Stacy Lewis plugged her ears and jokingly chanted, "La-la-la-la-la."
A few days and 72 exciting holes later, she was more than willing to talk.
Yes, the determined Texan who wore a back brace 18 hours a day for six years had jumped from third to first in the world with a comeback victory Sunday in the LPGA Founders Cup.
Diagnosed with scoliosis when she was 11, she thought back to her trying teen years.
"Every setback you have along the way, everything good that happens, it all happens for a reason," said Lewis, now 28. "I couldn't have dreamed the kid growing up wearing a back brace 18 hours a day is the No. 1 player in the world."
When the brace failed to correct the curvature in her spine, she had surgery to insert a rod and five screws in her back.
"That was just 10 years ago," Lewis said. "That's not normal, that's not supposed to happen. I mean, I'm not, I'm really not supposed to be here. People with metal in their back, how do you play golf? I don't know. I don't know how. I don't know why I'm here."
Coming off a victory two weeks ago in Singapore, Lewis won her seventh LPGA Tour title. She won the 2011 Kraft Nabisco and has six victories in her last 23 events, four last season when she was the tour player of the year.
"I'm having a blast on the golf course," Lewis said. "To be No. 1 in the world, it's what everybody out here on tour is working for."
She ended Yani Tseng's 109-week run at No. 1, and joined Cristie Kerr as the only Americans to top the rankings that began in 2006. Kerr was No. 1 for five weeks over three stints in 2010.
"It's crazy," Lewis said. "That was my goal kind of since the middle of last year and I really didn't think it would be possible this quick. ... I'm going to have fun, I know that. I watched Yani struggle with it for too long and I'm going to go have fun."
Lewis beat Ai Miyazato by three strokes, closing with an 8-under 64 to finish with a tournament-record 23-under 265 total on the cactus-lined Wildfire layout. Miyazato, three strokes ahead with six holes to play, finished with a 71.
The tournament turned with a three-stroke swing on the 16th hole, a day after Lewis was penalized two strokes for her caddie's blunder on the short par 4.
On Sunday, Lewis took a two-stroke lead with a birdie after Miyazato made a double bogey following an errant approach shot that left her with an unplayable lie in a desert bush.
Miyazato took a four-stroke lead over Lewis and Jee Young Lee into the final round when Lewis was penalized after play Saturday when it was ruled caddie Travis Wilson tested the sand before Lewis played out of a bunker on No. 16.
"I wasn't even mad at him because he didn't do anything on purpose," Lewis said. "I just felt really bad for him just because all the stories were, `Stacy Lewis' caddie, Stacy Lewis' caddie.' The spotlight was on him and he never wants that. We were so motivated today."
Miyazato was a stroke ahead on the 16th tee and seemingly in perfect position in the fairway on the 307-yard hole. But the straight-hitting Japanese star's pitching wedge sailed left, hit on the bank near the edge of the green and rolled into the desert bush.
"I hit the pitching wedge, but my instinct said that it was an easy 9," Miyazato said. "It was a little bit indecisive and that's why I pulled my shot."
Instead of playing again from the fairway, she elected to drop in sand in the desert, leaving her with an uphill shot with little green to work with. Her shot from the desert raced to the far edge of the green and she two-putted for a double-bogey 6.
"I decided I would take a drop almost like in a bunker position and I thought we had that little backstop behind the pin, so I thought I could make it stop a little bit more," Miyazato said. "It was kind of a little flat when I dropped, so it was hard."
Lewis, a 12-time winner at the University of Arkansas, found the right fairway bunker off the tee, hit to 15 feet and holed the birdie putt.
"I was shocked that she hit the shot she did," Lewis said. "That is not like Ai at all. She's green, green. I mean, it's boring to play with her because she hits so many greens."
Lewis added an 18-footer on the par-3 17th for her third straight birdie.
"To make those two putts I did on 16 and 17 was pretty unbelievable," Lewis said. "I'm really speechless. I played great and I was super motivated from all that happened yesterday and just happy for Travis.
"Weird things happen when you play enough golf rounds and I told him that over and over and over again. He would have felt horrible if we lost by two, so that's why I just put the dagger in and made some more putts there coming in."
When Lewis holed out on 18, she pointed at Wilson and hugged him.
"That's for you," she told him.
DIVOTS: Lewis earned $225,000 to push her tour-leading total to $526,364. She donated $50,000 to LPGA-USGA Girls Golf. ... Miyazato tied for second last year, a stroke behind Tseng. ... Angela Stanford was third at 17 under after a 68. ... Tseng shot a 70 to tie for 59th at 4 under. ... Lee, the second-round leader after opening 65-64, closed 72-72 to tie for fourth at 16 under.