Morgan Pressel became the youngest major champion in LPGA history yesterday with a game well beyond her 18 years, closing with a 3-under 69 at the Kraft Nabisco Championship in Rancho Mirage, Calif., as everyone around her self-destructed.

Pressel played her final 25 holes over Mission Hills without a bogey, finishing the round with a 10-foot birdie putt that looked as though it would be only good enough for second place.

Then came a shocking collapse from Suzann Pettersen, the latest and most significant on a sun-baked afternoon in the desert.

Pettersen, a fiery 25-year-old from Norway, had a four-shot lead with four holes to play when she started hitting tee shots into the ankle-deep rough and missing putts on the crusty greens. She went bogey-double bogey-bogey to fall one shot behind, and needing a birdie on the par-5 18th, she hit wedge some 25 feet beyond the hole and missed the putt.

"I said yesterday that a little help never hurts," Pressel said. "That rang true today."

Pressel, who finished at 3-under 285, was on the practice range when she entered the history books at 18 years, 11 months, 22 days.

Previously, the youngest major champion was Sandra Post, who was 20 years, 19 days when she won the 1968 LPGA Championship. On the men's tour, Young Tom Morris was 17 when he won the 1868 British Open.

Pressel broke down in tears over the shock and euphoria of winning a major 10 months after graduating high school.

"Oh my God! Oh my God!" was all she could manage.

Then came the sweetest pool party she ever attended. Keeping with tradition at the Kraft Nabisco, Pressel jumped into the pond surrounding the 18th green. With her were her caddie and her grandmother, Evelyn Krickstein.

Herb Krickstein, her grandfather and the father of former tennis player Aaron Krickstein, watched with a broad smile. Pressel came out of the water and slipped into a white robe that read, "2007 Kraft Nabisco Champion" on the back.

"This is a dream come true," Pressel said. "I knew I had to play solid golf. I couldn't make mistakes, I had to stay cool and be ready for whatever came."

It was hard to believe - not only at her age, but how it all unfolded. Se Ri Pak, needing to win this major to complete the career Grand Slam, had a three-shot lead on the front nine until Pettersen took charge with a four-shot swing over three holes. Pak bogeyed five of the last six holes for a 77.

Catriona Matthew, of Scotland, playing only her second event since becoming a mother 3 months ago, had a 30-foot birdie putt to reach 4 under when she three-putted for a bogey that left her in a tie for second with Pettersen and Brittany Lincicome (72).

But no one threw this tournament away more than Pettersen.

"I said [Saturday] that the one who made the fewest mistakes would win," she said. "I did a few too many."

It started with a tee shot into the right rough on the 15th, keeping her from reaching the green, and took a bogey. She went right again on the next hole, clipping a branch on her second shot that left her short of the green. Her wedge spun off the front of the green, and she used putter to ram it 8 feet by. The bogey putt caught the lip, and she was down to 3 under.

Pettersen then came up short on the 17th, chipped to 10 feet and missed again, falling one shot behind.

In other tournaments:

* At Humble, Texas, Adam Scott held off defending champion Stuart Appleby in the PGA Tour's Houston Open, saving par with a 50-foot putt on the 72nd hole after hitting his tee shot into the water. Scott shot a 6-under 66 to finish at 17 under, three strokes ahead of Appleby and third-round leader Bubba Watson.

* At Palm Coast, Fla., Keith Fergus bogeyed two of his last three holes to edge Mark O'Meara and Hale Irwin by a stroke in the Champions Tour's Ginn Championship to become the second player to win on the PGA, Nationwide and Champions tours. Ron Streck was the first. *