MORELIA, Mexico » Ai Miyazato is trying to spoil Lorena Ochoa's going-away party.

Miyazato, the Japanese star who won the first two events of the LPGA Tour season, shot a 10-under 63, the best round of her career in relation to par, to take the first-round lead yesterday in the Tres Marias Championship.

Spanish rookie Azahara Munoz opened with a 65, and the top-ranked Ochoa, who will retire after the tournament, matched Hawaii's Michelle Wie with a 66.

Miyazato won the Evian Masters last season—her first LPGA Tour victory—and has risen to No. 5 in the rankings. She's short off the tee—in the 240-yard range—but she may be the most accurate player in women's golf. She needed only 22 putts, most from 8-12 feet.

“;I don't feel like I'm playing so much better all of a sudden,”; Miyazato said. “;I feel like this is just one step at a time and building up my confidence. Last year gave me a lot of confidence. Just right now I am showcasing what I can do.”;

Miyazato had 10 birdies in her bogey-free round.

Ochoa asked to be paired with Miyazato and former University of Arizona teammate Natalie Gulbis in the first two rounds. Ochoa grew up in junior golf with Gulbis and called Miyazato “;the nicest girl on the tour.”;

“;I have played with her so many times since I have been on the tour, but today was really special,”; Miyazato said. “;Natalie and Lorena were really relaxed, so they had an effect on me and I played really relaxed.”;

Ochoa, stepping away to raise a family and work on her charity foundation, hinted that Miyazato is a candidate to eventually take over her No. 1 ranking. There's are many others, too, starting with No. 2 Jiyai Shin, No. 3 Yani Tseng and No. 4 Suzann Pettersen

“;I'm never seen somebody with so much control in her game,”; Ochoa said. “;It doesn't matter if she hits long, short, or low or high.”;

The surprise near the top of the leaderboard was Munoz, an LPGA rookie who is playing only her second event. But she has experience. She won the 2009 British Women's Amateur Championship and was the NCAA individual champion in 2008 at Arizona State.

“;Maybe I don't want to feel pressure,”; said Munoz, who grew up in Marbella on Spain's Mediterranean coast. “;I know everybody back home wants me to do well, and everyone is following me but I try not to think about it because it is not going to help me.”;

Like everyone, Munoz was trying to adjust to Morelia's altitude of 6,500 feet, where the ball flies about 10 percent farther. And she wants to play with Ochoa over the weekend.

“;I never got the chance to do it and it's her last tournament,”; she said.

Wie and Ochoa both started with eagles on their first hole—No. 10. The scores were low with little wind and favorable flag placements. It will change if the wind blows through the canyons surrounding this mountainside course.

“;There are a lot of birdies and eagles out there,”; said Wie, who picked up her only LPGA victory last season in Guadalajara in the Lorena Ochoa Invitational. “;It's a constant grind to keep making birdies, and even if you are making birdies you're not really above anyone else.”;

Ochoa has won the event three out of the last four years.

“;I woke up in the morning and told myself: 'We're here, this is the last tournament, let's enjoy the moment,' “; Ochoa said.