Ochoa shot a 7-under 65 in the third round of the Ginn Open on Saturday, moving to 16 under and taking a one-shot lead over rookie Yani Tseng.
The Mexican star is 18 holes away from her fourth victory in as many weeks.
She started the third round three shots behind Tseng and was four back after a bogey on No. 2. But the worlds No. 1 player made three consecutive birdies beginning with the par-5 ninth and took the lead for good with a near-perfect approach shot on No. 11.
She gave Tseng and a few others a chance to keep it close by just missing birdie putts on the next three holes. The 26-year-old Ochoa then closed out her round with birdies on 15 and 18, pumping her right fist after each one hit the bottom of the cup.
Tseng closed with birdies on two of her final three holes and shot 69. Teresa Lu (69) was 11 under, one stroke ahead of Carin Koch (70) and Suzann Pettersen (72).
Those three and everyone else are in an all-too-familiar position heading into the final round'trying to make up ground on Ochoa, who has won four of the five events shes entered this year.
Ochoas four victories have come by a combined 34 shots. She opened with an 11-stroke victory in Singapore, defended her Safeway International title with a seven-stroke romp, won the seasons first major by five shots and then went wire-to-wire last week in Mexico and won by 11.
She said Friday she prefers to play from behind, then backed it up.
Now, she will get to do what she does best'close out tournaments. Ochoa has won 15 of 22 times when having at least a share of the lead going into the final round.
One of her last losses? The Ginn a year ago, when she started that Sunday with a share of the lead, then endured a stunning collapse in blustery conditions.
Ochoa was 6 over on the final six holes, missed a 10-foot bogey try on No. 18 that would have forced a playoff and ended up with a 77.
She doesnt plan on letting that happen again.