The Mexican compiled a bogey-free 6-under 67 at St. Andrews in calm, sunny conditions on Thursday to take a two-shot lead in the Women's British Open. It was the first time the women pros had played at the famous course and she came up with the best opening round.
'I had in my head 2 or 3 under so it's even better than I thought.'
Ochoa finished well before lunch and then sat back to see if any of her rivals could catch up.
Sweden's Louise Friberg and South Korea's In-Bee Park are two behind after 69s with Japan's Ai Miyazato and England's Rebecca Hudson three off the lead after 70s. Annika Sorenstam had a 1-under 72 while Michelle Wie showed signs of straightening out her game with an even-par 73.
The strong winds that often blow across this part of Scotland took the day off and Ochoa took full advantage. The forecast for Friday and Saturday includes winds of up to 35 mph.
'I believe in myself and I was feeling good in the morning,' said Ochoa, who tied for second at the U.S. Women's Open a month ago and finished second, third and fourth in other majors. 'We are all excited to be here and I'm just glad I did it right on my first try and take as much advantage as you can and now I'm feeling good.
Many of the star names teed off early -- before 7 am local time -- for the benefit of live TV coverage in Asia and that suited Ochoa.
'It was a really early wakeup call but I don't mind that,' she said. 'I'm a morning person. I don't know how the next three days look and how the weather is going to be, but I'm happy I did it today.'
By the time she walked off the 18th green, few players out on the course were threatening her lead.
The 17-year-old Wie was two shots behind Ochoa until bogeys on two of the final five holes.
'It was semi-disappointing and semi-successful,' said Wie, who is recovering from an injured left wrist and has failed to break 70 in more than a year.
'It's the first time I've played really solidly, but I missed some reasonably easy putts. I'm starting to see a light at the end of the tunnel now.'
In perfect weather at St. Andrews, Ochoa birdied three straight holes and stretched her lead to three shots when her long approach to the 15th settled 2 feet from the pin.
That was her fifth birdie, and another followed at the 17th, the usually tough Road Hole which has been made a par 5 for the Women's Open and became the easiest to score under par.
Ochoa's second shot finished at the back of the green and her first putt left her with a 5-footer for birdie. After Miyazato bogeyed the 16th, Ochoa walked onto the 18th green four ahead of the field, then narrowly missed a 15-foot birdie on the final hole.
After winning her first title at the Evian Masters on Sunday, Natalie Gulbis didn't expect to be five behind at the turn. Without a birdie on the front nine, the American was 1 over after her bogey 5 at the second and went on for par 73, along with Paula Creamer.
U.S. Women's Open champion Cristie Kerr struggled to a 77, beginning her round with two bogeys.
'I've been putting way too much pressure on myself since the Open and it has backfired on me,' she said. 'I'm pushing it way too hard.'
Another major winner Morgan Pressel, who won the Kraft Nabisco, had even more problems. She finished at 80, which included nine bogeys.
Defending champion Sherri Steinhauer, who is going for her fourth title in this tournament, had a 72.