Morelia, Mexico ? Lorena Ochoa shot a 5-under 68 in the Mexican star’s first round as the No. 1 player in the world, leaving the defending champion a stroke behind leader Stacy Prammanasudh in the Corona Morelia Championship.

Ochoa, who took the top spot in the rankings from Annika Sorenstam on Monday, had two eagles, five birdies and four bogeys in windy conditions on the Tres Marias course, the Jack Nicklaus-designed layout that sits 6,300 feet above sea level.

After playing the back nine first, the 10-time LPGA Tour winner eagled the par-5 fifth and eighth holes, hitting a 7-wood from 216 yards to 21 feet on No. 5 and a 9-iron from 160 yards to 27 feet on No. 8.

Prammanasudh, the Fields Open winner in Hawaii in February, had four birdies and an eagle en route to her 67. South Korea’s Na On Min matched Ochoa with a 68.

Ochoa topped the world rankings Monday with 12.84 points, 0.14 points ahead of Sorenstam.