'This is an amazing feeling and I'm at a loss for words,' said Kim, who pocketed $138,000 for the win. 'To know that I am the champion of Champions, it's just amazing.'
Australian Rachel Hetherington carded a 4-under 68 on Sunday to finish alone in second place at minus-14. Overnight leader Liselotte Neumann of Sweden once held a two-shot lead on Sunday, but disaster on the back nine dropped her to a 1-under 71. Neumann took third at 12-under-par 276.
Juli Inkster played well on Sunday with a 3-under 69 and moved into fourth place at 11-under-par 277. Defending champion Heather Daly-Donofrio managed an even-par 72 and took fifth at minus-10.
Kim started well on Sunday with a long birdie putt at the third and added another birdie at the par-5 fourth. She dropped a shot at the seventh to fall two back of Neumann, as the Swede played tough on the front nine to keep her advantage.
Neumann birdied the second, then rolled in a 7-foot eagle putt at the fourth. She bogeyed the sixth, but ran home a 20-footer for birdie at seven to stay two in front.
Kim gave herself a tap-in birdie at the 11th, then, from the left rough, knocked her approach to six feet at 12. She converted the birdie putt and found herself tied for the lead.
The par-five 13th proved to be critical in Sunday's final round. Kim, who played with Hetherington in the group ahead of Neumann, made a routine par at the hole to stay at 14-under par.
Neumann hit her drive 40 yards right of the fairway and had to hit a provisional ball. She laid up with her fourth, then needed three more to get in the hole. The double-bogey left her two off Kim's lead.
'It was one bad swing,' acknowledged Neumann. 'I've been hitting the ball so well. What do you do?'
Neumann had more holes to make birdies, but it became clear that Hetherington was the closest challenger to Kim. Hetherington collected a pair of birdies on the front side and when her 4-foot birdie try at 14 fell, she was one behind Kim at 13 under par.
Kim reached the green in two at the par-5 16th and had a 20-foot look at eagle. Hetherington missed a 25-foot birdie putt at the same hole, so Kim could almost put the tournament out of reach if her eagle effort fell. Her putt skimmed the hole, but she settled for a tap-in birdie and a two-shot lead.
Kim stuffed her tee ball at the par-3 17th inside 5 feet. Hetherington had almost 12 feet for her birdie try, but poured it in the center of the cup. Kim's short putt lipped out of the hole, but she converted the par putt from almost the same distance as her birdie attempt.
Both Kim and Hetherington found the fairway at the closing hole and Kim's approach spun back to 45 feet. Hetherington did not hit a great second shot, but had a reasonable 35-foot chance at birdie.
Kim lagged her putt to a foot to put the pressure on Hetherington. The Aussie misread her putt, which died to the right and came up 2 feet short. Hetherington tapped in her par putt, then Kim kicked her's in to visit the winner's circle.
'This was, by far, more difficult than my win last year in Sacramento,' admitted Kim, who also won that tournament by a single shot. 'I don't know what I did. I hit it, try and find it and do it again. It stayed in the short grass for the most part and I'm thrilled to be here.'
Sophie Gustafson posted the low round of the day on Sunday with a 6-under 66. That propelled her into a solo sixth at 9-under-par 279.
Pat Hurst (67) and Carin Koch (68) shared seventh place at minus-8, followed by Janice Moodie (69), Heather Bowie (69) and Angela Stanford (72), who were knotted in ninth at 7-under-par 281.