'I don't think I got it, that I just won,' said Granada, a 17-year-old from Paraguay. 'I mean, it's such an honor. I see all the names on this trophy and I feel so special winning this.'
In an extremely tight final match, Granada took an early 1-up advantage after Park bogeyed the par-4 second. Park battled back with a birdie at the fourth, but Granada responded with a birdie of her own at the very next hole to remain 1-up.
Both players exchanged pars on the next five holes before each birdied the par-5 11th. Park made it two straight with a birdie at the par-3 12th to square the match.
Park, who never led on Saturday, fell 1-down again as she bogeyed the 13th, but picked up a birdie at the par-4 14th to pull even again.
Granada, who was the only of the three stroke-play medalists to survive the opening day of match play, showed the same persistence that saw her knock off Paula Creamer in the semifinals. She kept the match squared through 18 with the help of a 12-foot birdie putt at the par-5 17th after Park had reached the green in two.
'On the 17th hole coming down the fairway, I said to myself, 'How bad do you want it?',' said Granada. 'And when I made that putt on 17, I was like, 'Well, you want it really bad.''
She matched Park with a par on the 19th hole and Grenada took home the title after her challenger stumbled with a bogey at the 20th to become the first medalist to capture the tournament since In-Bee Park titled in 2002.
For Park, the runner-up finish was a reminder of last year's U.S. Women's Amateur when she finished second to Virada Nirapathpongporn.
'Golf only has one winner,' said Park. 'Second doesn't really do it for anyone.'