Grace Park, the third-round leader, only managed an even-par 72 and took second at minus-17. Jill McGill shot a 1-over 73 on Sunday and tied for third place with Hee-Won Han, who carded a 67, at 15-under-par 273.
Ochoa trailed by five shots at the start of Sunday's final round and Park took the lead into the back nine. Ochoa ran home a 6-footer for birdie at the second, then collected back-to-back birdies at the seventh and eighth to move up the leaderboard.
Park knocked her approach over the green at the 10th and made bogey. Ochoa holed a 5-foot birdie putt at the same hole and the lead was cut, but it was not until later in the back nine that Ochoa got into first.
Park landed in a greenside bunker at the 13th, and her 3-footer for par lipped out of the hole. That bogey dropped her into a tie for the lead with McGill, who birdied the 12th to join Park at 17 under par, one shot better than Ochoa.
The 15th hole proved to be the turning point. Ochoa ran her tee ball at the par-3 hole to 3 feet and converted the birdie putt to match the co-leaders in first.
McGill's shot at the same hole came up 40 feet short and Park missed the green right. Park pitched on to the fringe and missed her 40-footer. McGill three-putted for bogey and now that pair was one behind Ochoa.
At the par-5 16th, Ochoa missed the green short with her second, but putted to a foot. She tapped in for the birdie and two-shot lead, as Park parred 16 and McGill bogeyed the hole.
Ochoa gave her birdie try at 17 a good roll, but missed. She birdied the 18th to take an insurmountable three-shot lead into the clubhouse.
McGill bogeyed 17, but birdied 18 and Park birdied No. 18 to finish two shots from the lead.
'I will never forget this moment,' said Ochoa, who pocketed $150,000 for the win and is third on the money list. 'I thought I needed to go 8 under. I'm very happy 7-under was enough.'
This was Ochoa's second win of the season, as she also captured the Franklin American Mortgage Championship in May. The former NCAA standout at the University of Arizona joined Cristie Kerr, and major winners Annika Sorenstam, Meg Mallon and Karen Stupples as multiple winners this season.
'It is hard for me to put what I feel in words,' said Ochoa. 'I'm very happy it has happened for me. I had a great week.'
Beth Daniel shot a 4-under 68 on Sunday and took fifth place at 14-under-par 274. Christina Kim (66), Catriona Matthew (66), Shi Hyun Ahn (70) and Nancy Scranton (71) tied for sixth place at minus-13.
Young-A Yang (67), Marcy Hart (70) and Soo-Yun Kang (75) shared 10th at 12- under-par 276.