Lee carded a 1-over 73 in her final round to end the tournament at 5-under-par 211 and become the fourth straight Korean to win this event. She beat Carin Koch and Mi Hyun Kim by three strokes at Nine Bridges Golf Club.
One of 12 LPGA of Korea players in the field, the 19-year-old Lee led by two strokes at the end of the first round and by three strokes overnight. She was one of only seven women in this 69-player field to finish the tournament even-par or better.
Koch shot a 1-under 71 in her final round and Kim managed a 1-over 73 to finish at 2-under-par 214. Reigning Women's British Open champion Jeong Jang shot a 74 to finish tied for fourth place at minus-1 with LPGA of Korea player Hee Young Park (73).
Grace Park, the 2004 winner, finished at even-par 216 after a final-round, 2-under 70. She shared sixth place with Rachel Hetherington (72).
Annika Sorenstam had her best round of the weekend -- a 2-under 70 -- but ended nine strokes back in a tie for 14th place at plus-4. Sorenstam, who finished tied for second place with Koch last year, collected her eighth win of the season at the Samsung World Championship last week.
Lee won despite playing holes 14-18 at a combined 8-over-par in her second and third rounds. There simply wasn't a challenger willing or able to take advantage.
After beginning the day with a three-shot lead over Jang and Kim, Lee opened with a birdie at No. 1 to get to minus-seven. She dropped a shot at the par-3 second, but got it back with a birdie at the eighth to make the turn at 7 under.
Her third birdie of the day came at the par-5 12th, and after consecutive pars Lee went on to bogey three straight holes from the 15th to stumble to minus-5.
Janice Moodie and Sophie Gustafson fired matching 3-under 69s to finish tied for eighth place at plus-one. Shi Hyun Ahn, the 2003 champion, shot a final-round 72 and shared 10th place with three other players at 2 over.