Jennifer Kupcho went the four rounds of a total of 14 under par and secured her first victory on the LPGA Tour.
The 24-year-old from Colorado managed to row it into port despite a final round of 74 strokes, two over par.
- I have been so close a couple of times.
It's really that heavenly difficult sometimes, but here I am.
A major is crazy, says Kupcho after the victory, reports AFP.
Kupcho, who has previously been the world's best ranked amateur, not only wins the honor but also receives a prize money of five million dollars, corresponding to almost 47 million kronor.
Sagstgröm best Swedish
Thanks to his brilliant play last Saturday, Kupcho had a lead of six strokes before the final round - and the distance became impregnable for the runner-up, compatriot Jessica Korda, who ended up two strokes behind Kupcho.
Third place went to the Slovenian 18-year-old Pia Babnik, who made a huge finish and went the last round of 66 strokes, a total of eleven under par.
Best Swedish was Madelene Sagström, in a shared 13th place, six under par.
She made an even competition and went all rounds of 70 or 71 strokes.
Anna Nordqvist, who was in a split fourth place after the first day, crashed through the starting field and ended up far behind, two over par - two strokes behind the third Swede, Pernilla Lindberg.