Though Carin Koch is back to defend her Corona Morelia Championship, all eyes will be on Mexico's Lorena Ochoa, who will try for a fourth time to win in her homeland.

Ochoa sits atop the LPGA Tour money list, more than US$100,000 ahead of second-place Karrie Webb, who won last month's Longs Drugs Challenge. A good showing here _ the tournament has a $1 million purse, with $150,000 going to the winner _ would solidify Ochoa's lead since Webb and third-place Annika Sorenstam, the world No. 1, did not make the trip.

But playing in Mexico has been difficult for the 24-year-old Ochoa, who hails from Guadalajara, just 175 miles from Morelia. She has looked uncomfortable facing galleries packed with friends, family and fans, finishing tied for 16th at last year's Corona Morelia. She was also a non-factor at the 2005 and 2006 MasterCard Classic tournaments in Huixquilucan, outside Mexico City.

``We learned a lot in the tournaments before this one,'' Ochoa said. ``I feel better prepared. Obviously the local player feels a little more pressure, but I'll gladly take it.''

Koch also has some adversity to overcome. It has been 18 months since she won last year's Corona Morelia Championship, and her inconsistent play since then has made it feel even longer.

``I've been struggling and it hasn't been much fun,'' said the 35-year-old Swede. ``So that makes it even more fun to come back here to a place where I did well last year and just try to get my game back.''

Koch, who lives in Phoenix, used a consistent drive to win by six strokes at the inaugural event on Morelia's par-73, 6,600-yard Tres Marias course last April.

Carved into rolling hillsides, Tres Marias sits at an altitude of 6,300 feet, promising to help long-hitters like Ochoa. This year, the front nine is peppered with new sand traps, giving the course a different feel from 2005.

Ochoa said she was ``treating this like the most important tournament of my career because that's what it is.'' But she was quick to add that coming up short again in Mexico would not spoil her season.

``My mentality is a winner's mentality. I have had a very successful year, taken a lot of positive steps and what happens in one week doesn't mean everything,'' said Ochoa, who is tied for second in LPGA victories this year with three.

Koch said that she began the year hitting wildly and has only recently begun to recover. She will start the tournament Thursday paired with Ochoa _ which will mean massive crowds.

``I know they're not there to watch me,'' she said.

Natalie Gulbis is back after setting the course-record with a 66 in last year's opening round, before finishing tied for fifth. Also playing is 18-year-old sensation Morgan Pressel, who missed March's tournament in Mexico because she was still in high school.

The 2005 Corona Morelia was played in late April, but organizers pushed the date back this year so as not to follow the other Mexican event, the MasterCard Classic. Last year's tournament was delayed once by rain and lightning, but showers could be far more disruptive this year, with late-fall downpours coming daily about two hours before sundown.

Paula Creamer said a water-logged course could offset the high altitude.

``The golf course is so wet, it doesn't really come into play as much because the balls aren't going as far'' after they hit the ground, she said.

© The Canadian Press, 2007