Pressel broke down in tears after hearing of her win on the range
ROUND FOUR LEADERBOARD:
(US unless stated)
-3 M Pressel
-2 C Matthew (Sco), B Lincicome, S Pettersen (Nor)
-1 S Prammanasudh, S Hyun Ahn (Kor), M Francella, S Lewis
+1 L Ochoa (Mex)
+5 L Davies (Eng)
+9 A Sorenstam (Swe)
Morgan Pressel became the youngest major champion in LPGA Tour history after Suzann Pettersen's collapse gave her the Kraft Nabisco Championship.
Pettersen was three ahead with six to play but dropped four shots in her closing four holes to hand victory to the 18-year-old American.
Pressel finished on three under after a birdie at the last and learnt of the win on the practice range.
Catriona Matthew, Brittany Lincicome and Pettersen were one stroke behind.
"I said on Saturday that the player who made the fewest mistakes would win," said Petterson. "I did a few too many."
Petterson was also runner-up to Lorena Ochoa at last week's Phoenix tournament.
This is my first professional victory and to make it in a major is incredible
"This time, I felt like I lost the tournament," she
said. "Last week, I felt like I won second place."
Ochoa, whose hopes of taking over from Annika Sorenstam as world number one disappeared with a quadruple bogey on the 17th hole on Saturday, finished tied for 10th.
Sorenstam finished down in a share of 31st place on nine over - her highest score in a major since 1998 - after a final round of 75.
Pressel, who will be 19 next month, beat the record of previous youngest winner - Canada's Sandra Post - after claiming a birdie at the 18th from 12 feet.
"This is just a dream come true," she said. "This is my first professional victory and to make it in a major is incredible."
Pressel is the first American to win the event since Dottie Pepper in 1999.
The teenager had just missed out on winning the Women's US Open two years ago, having become the youngest player to qualify when doing so as a 12-year-old in 2001.
Scot Matthew had a chance to tie, but she three-putted the last from 30-feet for a bogey.
The 37-year-old became a mother in December and tied for fifth in last week's Safeway International in Arizona on her return from maternity leave.
"It was shame about the finish, but I've done much better than I expected on my comeback," she said.
"At the moment, I do feel disappointed but I'm sure I'll look back in a few days and realise how well I have played."