PRATTVILLE, Alabama, Sept 3, 2012 (AFP) - Lewis, whose only prior career title came at a major in last year's LPGA Kraft Nabisco, finished on 18-under 270 for 72 holes to beat defending champion Lexi Thompson by two strokes. The US teen star fired a closing 66.
"You have to hit it good here and hit some tricky putts," Lewis said. "It's stressful this course. Somebody can get on a good run and make a lot of birdies. And 16, 17 and 18 are tough finishing holes."
South Koreans Haeji Kang and M.J. Hur each fired 68 to share third with American Angela Stanford on 273.
Lewis also took the Shoprite LPGA Classic in June and the Mobile Bay LPGA Classic in April, where she also held off a final round charge by 17-year-old Thompson for a one-stroke triumph.
"She's a great player," Thompson said of Lewis. "Very consistent. Amazing putter."
Lewis stretched her lead in the LPGA Player of the Year race over World No. 1 Yani Tseng of Taiwan as the tour prepares for an Asian stretch ahead of November's season-ending Titleholders event in Naples, Florida.
"Same goals, go out there and try to win every week," Lewis said. "Player of the Year is the ultimate goal. This helps a lot."
Lewis stumbled early with a bogey at the second hole, answered with a six-foot birdie at the par-5 fifth, then followed with back-to-back birdies at nine and 10, from 18 and 10 feet respectively.
She addded another at the par-3 16th after dropping her tee shot 10 feet from the cup and parred the last two holes to seal the victory.
"I knew making that putt was key," Lewis said of her effort on 16. "It was downhill and it was so fast."
Thompson opened with a bogey, answered with birdies at the third and sixth holes, then birdied the par-5 eighth and 10th, the latter launching a run of three birdies in a row to close the gap on Lewis.
Lewis birdied the par-5 17th as well, electing not to charge after an eagle to try and chase down the leader.
"I just figured layup and birdie with my wedge. I've been more successful the last few years doing that," Thompson said.
The tour moves to Asia with events next month in Malaysia, South Korea and Taiwan and another at Japan in November.
Leading scores on Sunday after the final round of the $1.3 million Navistar LPGA Classic (par-72, USA unless noted):
270 - Stacy Lewis 66-70-65-69
272 - Lexi Thompson 63-69-74-66
273 - Haeji Kang (KOR) 70-68-67-68, M.J. Hur (KOR) 68-65-72-68, Angela Stanford 67-68-68-70
274 - Beatriz Recari (ESP) 70-71-66-67, Sarah Jane Smith (AUS) 69-69-68-68
275 - Meena Lee (KOR) 70-67-71-67, So Yeon Ryu (KOR) 69-69-69-68, Hee Young Park (KOR) 65-69-72-69
276 - Azahara Munoz (ESP) 72-66-73-65, Pernilla Lindberg (SWE) 70-68-71-67, Jennifer Johnson 71-65-71-69
277 - Nicole Castrale 69-68-70-70, Dori Carter 67-67-73-70
278 - Dew Claire Schreefel (NED) 71-69-72-66, Sandra Gal (GER) 68-71-72-67, Mina Harigae 69-72-67-70, Sydnee Michaels 67-68-72-71, Lizette Salas 65-69-70-74
279 - Suzann Pettersen (NOR) 71-71-71-66, Belen Mozo (ESP) 70-68-73-68, Wendy Ward 66-73-72-68, Brittany Lincicome 72-70-68-69, Amy Yang (KOR) 69-71-69-70, Karin Sjodin (SWE) 70-67-72-70, Gerina Piller 68-67-74-70