'I am very happy,' said Sorenstam. 'It has been a wonderful week. I thought I played some great golf, so I am very happy to be the winner today.'
Grace Park, who won last week's CJ Nine Bridges Classic, carded a 67 to join Ai Miyazoto (63) and Michie Ohba (63) in a tie for second place at 13-under-par 203. Aree Song and Junko Omote shot matching rounds of 68 to share fifth place at 12-under-par 204.
Sorenstam has set many records throughout her career and her victory Sunday at Seta Golf Course put her alongside Laura Davies as the only players in LPGA history to win the same event four consecutive times. The win also moves Sorenstam into a tie for fourth place with Betsy Rawls on the LPGA all-time wins list with 55 career victories.
Sorenstam held a four-shot lead heading into the final round and parred each of her first four holes on Sunday. That streak ended with a birdie at the par-3 fifth followed by an eagle at the par-5 sixth after Sorenstam's second shot stopped within 8 feet of the hole.
'You never know what can happen, but when I made eagle on six I felt pretty good,' said Sorenstam. 'You can never take anything for granted, but I felt pretty comfortable then.'
The Swede then hit a wedge to 4 feet for a birdie at the par-4 seventh and knocked her approach inside 9 feet at the very next hole. Sorenstam drained the putt for another birdie to move to 20 under around the turn.
Sorenstam kept on cruising with another string of pars until she hit her second shot to 6 feet for a birdie at the par-4 14th.
Sorenstam then dropped her tee shot within a foot of the hole at the par-3 16th and tapped in for birdie to equal her margin of victory from last season.
'I think certain parts of my game have improved every year,' said Sorenstam, who posted her seventh victory of 2004. 'I think I have become a better player, and I think experience helps too.'
Karrie Webb, Hee-Won Han, Young Kim and Chieko Amanuma tied for seventh place at 11-under-par 205. Davies was one shot further back along with Candie Kung and Jamie Hullett at 10-under-par 206.
Chihiro Nakajima, who shared the first-round lead with Sorenstam, struggled to a 74 on Sunday to finish well off the pace at 9-under-par 207 alongside Gloria Park and Stacy Prammanasudh.