PHOENIX -- Stacy Lewis won the RR Donnelley LPGA Founders Cup on Sunday to jump to No. 1 in the world, taking advantage of Ai Miyazato's collapse on the 16th hole.
A day after Lewis was penalized two strokes for her caddie's blunder on the short par 4, the American took a two-stroke lead with a birdie on the same hole after Miyazato made a double bogey following an errant approach shot that left her with an unplayable lie in a desert bush.
Coming off a victory two weeks ago in Singapore, the 28-year-old Lewis won for the seventh time in her LPGA Tour career to end Yani Tseng's 109-week run at No. 1.
"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 closed with an 8-under 64 at Desert Ridge to finish with a tournament-record 23-under 265 total on the cactus-lined Wildfire layout. She won the 2011 Kraft Nabisco Championship for her first tour title and has won six times in her last 23 events.
"I'm having a blast on the golf course, and to be No. 1 in the world, it's what everybody out here on tour is working for and to be that person is, I mean, I really don't even know what to say," said Lewis, the LPGA Tour Player of the Year last year after winning four times.
Miyazato finished second, three strokes back after a 71.
"All in all, I had a good day," Miyazato said. "I have a good feeling and my play was really solid, just the one bad shot on 16. I was a little disappointed."
The Japanese star took a four-stroke lead over Lewis and Jee Young Lee into the final round as Lewis was penalized after play Saturday when it was ruled that 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."
Forced to wear a back brace for 18 hours a day for six years as a teen because of scoliosis, Lewis is the second American to top the rankings that began in 2006. Cristie Kerr was No. 1 for five weeks over three stints in 2010.
"Almost 10 years ago, I was having surgery," Lewis said "I was going into surgery to put a rod and five screws in my back. 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. I know that there's a reason and I know that everything happens for a reason."
Miyazato took a one-stroke lead into the 16th and was seemingly in perfect position after hitting in the middle of the fairway on the 307-yard hole. But her pitching wedge sailed left, hit on the bank near the edge of the green and rolled into the desert bush.
"My shot was like totally in between clubs," Miyazato said. "I hit the pitching wedge, but my instinct said that it was an easy 9, so 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 went 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, the Texan who won 12 tournaments at the University of Arkansas, found the right fairway bunker off the tee on 16, hit to 15 feet and holed the birdie putt for a three-stroke swing.
"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 made an 18-footer on the par-3 17th for her third straight birdie to open a three-stroke lead.
"I was certainly surprised she finished the way she did, but to make those two putts I did on 16 and 17 was pretty unbelievable," Lewis said. "I'm just 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."
Miyazato also tied for second last year at Desert Ridge, a stroke behind Tseng. She was playing for the first time since sustaining a whiplash injury in a five-vehicle crash in Bangkok after the Honda LPGA Thailand.
Divots: Lewis earned $225,000 to push her tour-leading total to $526,364. She donated $50,000 to LPGA-USGA Girls Golf. ... Angela Stanford, another Texan, 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.