Lee, the 22nd seed, picked up her second LPGA Tour title.
'I felt really great and really confident this week,' said Lee, who collected $500,000 for the win. 'This is my second win on tour and it means a lot to me.'
For the third straight year, a double-digit seed walked away with the title. In 2005, 60th-seeded Marisa Baena won, then 39th-seeded Brittany Lincicome took home the title last year.
Miyazato bogeyed the first, but Lee then bogeyed No. 2 to square the match. Lee won the next two holes with pars and she would lead the rest of the way. The duo halved the next six holes.
Lee was unable to save par from a greenside bunker at the 11th as her lead slipped to 1-up. Miyazato knocked her second shot over the green at 12 and could not get up and down for par from there to again fall 2-down.
Lee, who is from South Korea, made a mess of the 14th and conceded a birdie putt to Miyazato. Lee atoned for that mistake at 16. Her second shot found a divot in the fairway, but she played her third at the par-5 to 6 feet and she drained the birdie effort.
Armed with a 2-up lead with two holes to go, Lee took dead aim at the pin on the par-3 17th at Wykagyl Country Club. Her ball rolled by the edge and stopped 8 feet from the cup. Miyazato responded by dropping her tee shot inside of Lee's.
It did not matter, as Lee sank the 8-footer for the 2-and-1 win.
'I loved this golf course. It was in great shape,' stated Lee. 'I liked putting here because the greens were fast and true.'
'She played really good and had a good poker face,' Miyazato said of Kim. 'I just tried to focus on my own game.'
Miyazato, who won the 2005 LPGA Tour Qualifying Tournament, was denied winning her first tour event.
'Can I get a little more time?' joked Miyazato when asked about getting her first win. 'I really played well this week though.'
Mi Hyun Kim fended off Maria Hjorth, 2-up, in the consolation match.