ANCHO MIRAGE, April 7, 2014 (AFP) - The 19-year-old American Thompson fired a closing four-under 68 for a 14-under par total of 274 in the US tour's first major of the season.
That gave her a three-stroke win over Wie, who finished with three bogeys in the final round en route to a one-under 71.
"I worked my life to win a major. This was my main goal," Thompson said. "Overall it was a pretty solid week. This tournament is special to me."
Thompson, who is 19 years, one month and 27 days old, becomes just the second youngest to win a women's major championship.
Thompson, who held a share of the third-round lead, clinched the victory by sinking a one-foot putt on 18.
She sank the winning putt and was mobbed by her family members who poured beer over the teenager's head.
Thompson then celebrated with a jump into the water hazard next to the 18th green with her caddie and entourage in tow. The jump into Poppy's Pond is a tradition at the Palm Springs-area tournament.
"I have always visualized myself jumping into that pond," Thompson said. "I went with the half cannon ball. I was going to take my shoes off."
The 24-year-old Wie made it easy for Thompson as she finished with three bogeys, including on the par-three No. 8 and the par-three 17. Wie had four birdies to shoot one-under on the day and finish with a 11-under 277 total.
Wie putted first on 17 missing a short putt and then making bogey, giving Thompson a four-shot lead heading into the final hole. Wie birdied the last but it was too late.
"I couldn't get anything going," she said.
The former teen phenom has failed to live up to the early hype in her career.
Wie has two career wins on tour but none since the 2010 Canadian Women's Open. She won in Mexico in 2009 but has yet to win a full tournament in the United States.
Wie has never learned how to close in tournaments on a consistent basis. She said mental mistakes cost her the Sunday title. Wie was unable to make the needed changes in her game plan when she began to fall behind.
"I got to a point where I just tried too hard. I tried to make birdies and forced everything," Wie said. "I wanted to make those putts so badly I just forced it."
Thompson's bogey-free round included four birdies, all on the front nine. She birdied three of the first five holes and was feeling confident at the turn.
"I didn't look at the leaderboard until number nine," said Thompson who earned $300,000 in first place prize money. "I was nervous on the first hole. But then I just tried to relax.
"Golf is all about confidence. I was trying to stay in the moment and focus on one shot at a time. Just focus on my routine."
Women's world number one and last year's winner Park In-Bee stumbled to a three-over 75 to fall into 38th at four-over 292.
Leading final-round scores on Sunday in the LPGA Kraft Nabisco Championship, first women's major of the year (USA unless noted, par-72, a-denotes amateur):
274 - Lexi Thompson 73-64-69-68
277 - Michelle Wie 67-71-68-71
281 - Stacy Lewis 73-70-69-69
282 - Cristie Kerr 69-70-71-72, Se Ri Pak (KOR) 67-70-71-74
283 - Feng Shanshan (CHN) 66-73-72-72
284 - Angela Stanford 74-69-69-72, Azahara Munoz (ESP) 72-70-70-72, Charley Hull (ENG) 73-69-66-76
285 - Amy Yang (KOR) 68-73-71-73
286 - Catriona Matthew (SCO) 72-68-70-76, Karrie Webb (AUS) 73-70-70-73, Morgan Pressel 70-70-75-71, Gerina Piller 77-65-70-74, Caroline Masson (GER) 73-72-72-69
287 - Christina Kim 74-69-72-72, Choi Na-Yeon (KOR) 72-71-72-72, Lee Jee-Young (KOR) 71-75-67-74, Shin Ji-Yai (KOR) 69-73-70-75, Anna Nordqvist (SWE) 71-69-74-73, Tiffany Joh 70-75-70-72, Chella Choi (KOR) 70-72-69-76, Lee Mi-Hyang (KOR) 72-72-72-71