That score tied her own scoring record for the event, which she first posted in 1998. Sorenstam titled here in 1998 and 2002. She won for the fifth time in seven starts this season and now owns 61 career wins.
Juli Inkster, the 1986 and 1988 champion, closed with a three-under 68 to take second place at 13-under-par 200. Catriona Matthew also fired a 64 to share third place with Laura Davies at minus-12.
Davies actually birdied the first three holes to take the early lead at minus-12. However, she could only manage one more birdie and one bogey over her final 15 holes at the Seaview Resort Bay Course.
Sorenstam meanwhile opened with four straight pars. She moved within one shot of Davies with a birdie at the fifth. The Swede parred her next three holes before collecting her second birdie at the ninth.
That birdie gave her a two-stroke cushion over her playing partner, Inkster. Sorenstam, who is the two-time defending champion at next week's McDonald's LPGA Championship, birdied the 10th to move to 13 under.
Sorenstam picked up her fourth birdie on the 13th, to move two clear of Inkster, who had birdied 10 and 12. The 34-year-old Sorenstam birdied the 17th before closing the tournament in style with an eagle at the last.
'I can't believe the finish. I thought I played really good on the back nine,' said Sorenstam, who picked up $210,000 for the win. 'I thought the back nine has been my mine this week. Obviously I am very happy, but you never know what could happen out there. I had to fight to the end.'
Inkster was never really a factor on Sunday. She birdied the third, but dropped a shot at six.
Around the turn, Inkster collected a birdie on No. 10 and got to 12 under with a birdie from 10 feet out at 12. That got her within one of Sorenstam, but she only managed one more birdie, at 17, coming in.
'I played really well, but No. 6 killed me,' said Inkster, who has finished second behind Sorenstam in all three of Sorenstam's wins at this event. 'I thought I hit some good putts, they just didn't go in. I just needed to play great to win.'
Jeong Jang and Pat Hurst shared fifth place at 8-under-par 205. Jimin Kang tied the course record of 62 that Davies set on Saturday. Kang finished at minus-7 alongside Mi Hyun Kim in seventh place.
Joanne Morley and Natalie Gulbis tied for ninth place at 5-under-par 208. Stacy Prammanasudh and 2004 champion Cristie Kerr ended one stroke further back at minus-4.