If Ochoa wins today, the 26-year-old Mexican star will become the youngest player to qualify for the Hall of Fame. Se Ri Pak was 26 years and a few months older than Ochoa when she qualified by winning the 2004 Michelob Ultra Open.
The LPGA Tour awards one point for every victory and major award and two points for a major victory. Ochoa still must play 10 years on the LPGA Tour before she becomes eligible for the Hall of Fame, a goal she would reach in the 2012 season.
Ochoa also is in position for her third victory in a row and fourth in five starts this season. She entered the week with 20 LPGA Tour titles.
South Korea's Inbee Park (70) was second at 16 under par, and compatriot Song-Hee Kim (71) followed at 13 under par.
Ochoa, a stroke ahead of Park heading into Saturday, pulled away from the pack with seven birdies, including four in a row on Nos. 8-11.
A victory today would be her second at the rugged Tres Marias course; Ochoa won the 2006 Corona event, her only tournament win on Mexican soil.
Ochoa has won over hearts in Mexico. Her face is on billboards around the country, and her success is celebrated as among the greatest achievements in Mexican sports history.
As Ochoa moved along the course, people constantly lined the fairways, cheering her every move.
As she prepared to hit a long approach iron over water onto the eighth green amid strong wind, two young sisters in matching dresses pulled loose some grass and threw the blades into the air, testing the direction of the gusts. Farther away, in the shade of several willow trees, a young girl hit a plastic golf ball with a plastic club, glancing up at Ochoa to see if she was getting it right.
Ochoa has made golf popular in a developing country where the game used to be only for the super rich and vacationing foreigners.