HUIXQUILUCAN, Mexico (AP) _ Annika Sorenstam was careful not to get too far ahead of herself after a good start in her first LPGA Tour event of the season.
``You can never really win a tournament on the first day, but I feel sometimes there's a chance you can lose it by shooting a high score,'' Sorenstam said. ``So I'm very happy with this start. It was really the start I wanted.''
Sorenstam opened her MasterCard Classic title defense Friday with a bogey-free, 5-under 67 for a share of the lead with Italy's Silvia Cavalleri.
The Swedish star is making her first official LPGA Tour start since winning the ADT Championship in November and her first competitive appearance since teaming with Liselotte Neumann in January to win the Women's World Cup in South Africa.
``I'm very, very happy,'' Sorenstam said. ``I have had a nice offseason and then to come back here to defend, and I don't want to say pressure, but I wanted to perform because I feel like I have had a good practice season the last two weeks. I felt really good about my game, but you never know until you come out here and start putting your score together. You know what, I could not have asked for a better day.''
Because of Bosque Real's hilly terrain and long distances between holes, players and caddies used carts for the first time in tour history.
``I prefer walking, but then again this course is very tough to walk,'' Sorenstam said. ``I think using carts was the right thing to do. I think it will speed up play. At the beginning it was tough to get your rhythm. Normally, you have the bag there and you grab a club. Now, you have to find a new system with your caddie. ... For the first six or seven holes, I couldn't really find a rhythm, but then in the end it was fine.''
Last year at Bosque Real, Sorenstam won in her first tour start of the year, closing with a 68 for a three-stroke victory. She won 10 times in 20 tour starts last year to push her career total to 66 _ 22 short of Kathy Whitworth's record.
On Friday, Sorenstam opened with a birdie, hitting a pitching wedge to 3 feet on the 419-yard first hole. She hit a sand wedge to 3 feet to set up another birdie on the 512-yard sixth, and got to 3 under with a sand wedge to 6 feet on No. 10.
With the wind gusting on the back nine, she got up and down for birdie from a greenside bunker on the par-5 12th, and hit a sand wedge to 7 feet to set up another birdie in the 584-yard 18th.
``The wind definitely picked up,'' she said. ``It was gusting at times. It makes it very difficult with the elevation changes. You have to play the ball a little lower and keep it under control a little bit more. You don't want the ball to climb.''
Cavalleri, winless on the tour, had seven birdies and two bogeys.
``I putted very well,'' she said. ``It was just a steady round apart from two bogeys in the last five holes.''
Norway's Suzann Pettersen, limited to nine tournaments last year because of a back injury, opened with a 68, and Lorie Kane, Carin Koch and Mi Hyun Kim had 69s.
Natalie Gulbis was three strokes back at 70 along with Fields Open winner Meena Lee, Danielle Ammaccapane, Nicole Jeray, Lee Ann Walker-Cooper and Seon Hwa Lee.
Hundreds of fans turned out to cheer Lorena Ochoa, the 24-year-old Guadalajara native who won the Rochester LPGA last year for her third tour title.
Ochoa had three bogeys and one birdie in a 2-over 74.
``The truth is I hit the ball well and I'm a little frustrated I didn't make more birdies,'' Ochoa said. ``The key was I didn't make a lot of putts because I wasn't close to the hole. I left myself very long putts for birdie.''
She struggled in the spotlight a year ago, but rallied to finish fifth.
``I'm really very relaxed, much more so than last year,'' she said. ``I'll continue to be relaxed and I hope that can help me tomorrow.''