The win was Pak's first of the 2004 campaign and her 22nd since joining the LPGA Tour in 1998. The victory on Sunday qualified her for the LPGA Tour Hall of Fame, but she will not be enshrined until 2008. A golfer must have played 10 years on tour to qualify for the Hall of Fame.
'This means a lot,' said Pak, 26. 'This is what I worked so hard for the last seven years. Finally I've done it. Now I can feel free to play and hopefully enjoy it.'
Inkster posted a 4-under 67 on Sunday while Ochoa, who shared the third-round lead in an attempt to earn her first LPGA Tour title, only managed an even-par 71.
Hee-Won Han carded a 5-under 67 and tied for fourth place with Wendy Doolan. Doolan shot a 1-under 70 and joined Han at 4-under-par 280 on Sunday.
Michelle Wie, the 14-year-old amateur star, posted a 1-over 72 and tied for 13th place at even-par 144.
Pak, who trailed by four at the start of Sunday's final round, flew out of the gate with three birdies in her first five holes. She dropped a shot at the sixth, but Pak was near Ochoa's lead right before making the turn.
Pak sank a 20-foot, left-to-right breaker for birdie at the eighth, then holed a 4-footer for birdie at No. 9 to get within one of Ochoa's lead.
When Pak rolled home a 6-foot birdie putt at the 11th, she matched Ochoa in first at 8-under par. Ochoa dropped strokes to par at the ninth and 10th, leaving Pak alone atop the leaderboard.
Pak padded her advantage with a 12-foot birdie putt at the 14th. She missed the green in two at the par-5 15th, but chipped close and converted the birdie try. Ochoa bogeyed the 14th so Pak was comfortably out in front.
Inkster eagled the 15th, then birdied No. 17 to reach minus-7, but needed several miscues down the stretch from Pak. Inkster got one mistake from Pak as the newest Hall of Famer missed the green long and left at the 16th. Pak's chip came up 25 feet short and she missed the par putt to fall back to 9 under par.
Pak settled after the hiccup at 16. She had seven feet for birdie at 17 and 15 feet at the last but missed both. It would not matter as Ochoa did not make up any ground and Pak was on her way to the winner's circle.
'Golf's kind of funny,' said Pak, who pocketed $330,000 for the win. 'I was struggling earlier this week. Yesterday I started making more putts and my confidence came back.'
Cristie Kerr, who shared the lead with Ochoa after Saturday's third round, struggled to a 4-over 75 in Sunday's final round. She tied for sixth place with Mi-Hyun Kim, who shot a 2-under 69, at 3-under-par 281.
Annika Sorenstam, the top-ranked player in the game, carded an even-par 71 and shared eighth place with Pat Hurst and Helen Alfredsson, who both also shot 71s on Sunday. The trio came in at minus-2.
Karrie Webb fired a 67 for a solo 11th-place finish at minus-1 and 2003 winner Grace Park was among the group with Wie at even-par 284.