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 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.
Lewis closed with an 8-under 64 in perfect conditions at Desert Ridge to finish with a tournament-record 23-under 265 total on the cactus-lined Wildfire layout.
Miyazato finished second, three strokes back after a 71.
The Japanese star 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 that caddie Travis Wilson tested the sand before Lewis played out of a bunker on No. 16.
Forced to wear a back brace for six years as a teen because of scoliosis, Lewis is the second American to top the ranking that began in 2006. Cristie Kerr was No. 1 for five weeks over three stints in 2010.
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.
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. Hitting her fourth, her shot from the desert went to the far edge of the green and she two-putted for a double-bogey 6.
Lewis, the Texan who won 12 tournaments in her college career at the University of Arkansas, found the right fairway bunker off the tee, hit to 15 feet and holed the putt for a birdie. She then made an 18-footer on the par-3 17th for her third straight birdie and a three-stroke lead.
Miyazato was playing for the first time since sustaining a whiplash injury in a five-vehicle crash in Bangkok after the LPGA Thailand. She withdrew the following week in Singapore as a precaution because of stiffness in her neck, shoulder and back.
Miyazato also tied for second last year at Desert Ridge, a stroke behind Tseng.
DIVOTS: Lewis earned $225,000 in the $1.5 million event. ... Angela Stanford was third at 17 under after a 68. ... Tseng shot a 70 to tie for 59th at 4 under. ... Jee Young Lee, the second-round leader after opening 65-64, closed 72-72 to tie for fourth at 16 under.
More Sports Headlines
Snohomish mixed martial artist returns to her first love Mariners beat Twins 4-3 in 11 innings Charles scores 29 points, Liberty beat Storm 78-62 Park wins Women's British Open, captures 4th different major Perry wins 2nd straight Champions Tour's 3M Championship Merritt shoots 67 to win Quicken Loans National by 3 shots Triple Crown winner American Pharoah wins $1.75 million Haskell Invitational Bills' Ryan names Incognito starting left guard
Our new comment system is not supported in IE 7. Please upgrade your browser here.