Park didnt make a bogey over the final 10 holes, pulling away with three clutch putts early on the back nine and building a four-shot lead going to the final hole. She finished with a tap-in birdie, and a few of her fellow South Koreans doused her with beer.
The victory came 10 years after Park took up the game, inspired by watching Se Ri Pak win the Womens Open at Blackwolf Run to become the youngest champion at age 20.
Its really an honor and very special for me that I won the event 10 years after I start playing, Park said. Everything happened so fast. Its scary. I really tried to stay calm, but it was so exciting, I couldnt do it. This is my day.
Park finished at 9-under 283 and earned $585,000 from the richest purse in womens golf. Her four-shot victory over Helen Alfredsson of Sweden, who shot 75, was the largest in the Womens Open since Karrie Webb won by eight shots at Pine Needles in 2001.
No one imagined the only drama on the back nine would come from Annika Sorenstam, who was never in contention competing in her final Womens Open before retirement at the end of the season.
Her final shot was a 6-iron from 199 yards that tumbled into the cup for eagle.
Leaving with another great memory, thats for sure, Sorenstam said after closing with a 78 to finish 12 shots behind in a tie for 24th. Maybe not the one I had in mind, but Ill take it.
Such highlights were rare for everyone else.
Stacy Lewis, trying to become the first player to win a major in her professional debut, took double bogey from 80 yards away on the par-5 second hole and struggled all afternoon with her lag putting. She staggered home to a 79 and tied for third at 4-under 288 with Angela Park (73) and In-Kyung Kim (75).
I finished third at the U.S. Open, my first pro event, Lewis said. Its kind of hard to be upset.
An even greater collapse came from Paula Creamer, 21, who said her experience from six LPGA Tour victories would be a big advantage. She then shot 41 on the front nine, including two double bogeys, and wound up with a 78 to tie for sixth.
Creamers final round scoring average in the U.S. Womens Open is 75.2.
Its probably the most disappointed Ive been in a very long time, she said.
Park was the only player to break par all four days at Interlachen, a course that showed its strength in the final round with 20 mph wind that made it tough to keep on the right side of the hole.
The lowest score Sunday belonged to 15-year-old Jessica Korda, the daughter of 98 Australian Open tennis champion Petr Korda, who caddied for her. She shot a 69 and tied for 19th.
Park became the third player in the last six years to make the U.S. Womens Open her first LPGA Tour victory, and it was reminiscent of Birdie Kims victory three years ago at Cherry Hills, minus the dramatic bunker shot for birdie on the 72nd hole.
There were so many possibilities for great story lines going into the final round'Lewis and her remarkable recovery from back surgery that almost ended her career before she got to college; Creamer, looking poised to finally get a major to go with her marketing campaign; Alfredsson, who blew a six-shot lead at the Womens Open in 1994, now with a chance for redemption at 43.
Instead, it was Park who stole the show by simply playing the best golf.
She was tied for the lead with Lewis after a bogey on the 234-yard eighth hole, falling to 7 under, then escaped with a nifty par on the diabolical ninth hole after her approach rolled off the front of the green.
In the group behind her, Lewis three-putted from about 60 feet on the eighth, then went long of the ninth and did well to make bogey. Equipped with a two-shot lead, Park poured it on.
She holed a 10-foot birdie putt on the 11th hole to expand her lead to three shots, holed an 8-foot putt to save par from the bunker on the par-3 12th, then chipped to 6 feet and made birdie on the par-5 13th to reach 9 under, giving her a four-shot lead with five holes left.
Even under such pressure, she was steady to the very end.
Park continued international dominance of the LPGA majors, as Americans have won only six of the last 31.
Lorena Ochoa of Mexico, who had finished no worse than third in the last four majors and won two of them, never got on track at Interlachen and closed with a 74 to tie for 31st.
The loudest cheer of the week at Interlachen was saved for Sorenstam, and it was more than ceremonial.
Sorenstam is retiring at the end of the season, and no major has defined her career more than the Womens Open, which she has won three times. But she was headed for an 80 in her final round after driving into the rough on the par-5 18th and having to chip out.
Then came her grand finale. Her 6-iron bounded onto the green and dropped in for an eagle and a 78.
I didnt want to shoot 80 or above, she said. And to hole a shot from 200 yards, thats kind of the last thing you think about. But obviously, Ill take it.
Editor's Note: Don't miss the live U.S. Women's Open blog, as well as other championship coverage, from partner Golf for Women magazine at golfforwomen.com.