After three rounds, Ochoa led In-Kyung Kim by one shot. She missed a half-dozen chances on the front nine, lipping out three times, and her bunker shot on No. 10 rolled 35 feet past the hole for a bogey that dropped her back into a tie.
She missed from 12 feet for bogey on No. 12 and from 5 feet for another bogey on No. 14. But she finally caught up on No. 18 when Kim had to chip out of the rough behind the green and then lipped out.
Both players made par on the first playoff hole. After wayward drives on the next hole - the par-4 10th - Ochoa sank a 3-foot par putt while Kim missed from 15 feet away.
Early this month, Ochoa let a two-shot lead slip away over the final two holes at the Ginn Tribute, handing Nicole Castrale her first LPGA Tour victory in a playoff.
Ochoa was runner-up here in her rookie year in 2003 and won in 2005 when she birdied six of the last seven holes to beat Paula Creamer by four strokes. She has 11 top-10 finishes this year, winning the Safeway International in March and the Sybase Classic in May.
Ochoa topped the 2006 money list with $2.59 million, just $4,632 more than Sweden's Annika Sorenstam. For the previous 11 years, either Sorenstam or Karrie Webb of Australia had ranked No. 1 in official earnings.