The 25-year-old Mexican star might have to settle for gaining the top spot a different way — with Sorenstam injured and out of the mix.

Ochoa shot a 6-under 66 in the opening round of the Ginn Open today, tying Laura Davies for the lead and moving a step closer to supplanting Sorenstam atop the rankings.

"I would love for her to be playing, yes," Ochoa said. "So I guess right now it's the way it is. But I think I better keep playing good and just take advantage of that. But I wish her all the best. Hopefully she will be (back soon)."

Sorenstam will be sidelined at least a month because of a ruptured disk in her back. She withdrew from the Ginn on Thursday and planned to see a neurosurgeon in Miami to figure out what to do next.

"I've been playing with quite a bit of pain for the past several weeks," Sorenstam said in a statement. "I couldn't take it much more and decided it was time to see someone."

Sorenstam, a 10-time major winner, said doctors discovered a ruptured disk and a bulging disk. It marked the first significant injury in her 13-year career that includes 69 LPGA Tour victories.

Sorenstam was never a factor in the first major of the year, the Kraft Nabisco Championship two weeks ago. She shot 8-over 296 for her highest 72-hole score in a major in nine years.

Ochoa could have taken over the top spot in the rankings with a victory there. But she tied for 10th after closing with a 72. Her hopes of winning her first major and overtaking Sorenstam in the rankings were essentially ruined with a quadruple bogey on No. 17 in the third round.

She hasn't thought much about the one bad hole since.

Instead, she focused on playing better to start tournaments. She opened with a first-round 71 in each of the first three events. She was considerably better in the last two — she was second after the first 18 holes at the Kraft — but she hadn't been atop the leaderboard as soon as she wanted.

Until now.

She took advantage of solid iron play and soft greens to make eight birdies on the 6,505-yard course near Orlando.

"It feels better," Ochoa said. "I don't feel in a rush that I need to just come (Friday) to go really low. ... It does make a big difference."

The 43-year-old Davies, a 20-time winner whose last tour victory came in 2001, made five birdies and an eagle en route to her lowest round of the year.

"I've played really well this year without too much success," said Davies, whose best finish in five events is a tie for 13th.

Brittany Lincicome, in the same group as Ochoa, fed off her playing partner's success and was a stroke behind at 5 under. Na Ri Kim, Sherri Turner and Mi Hyun Kim were 4 under.

Morgan Pressel, who became the youngest major champion in LPGA history with her victory at the Kraft, shot 75 and was nine shots off the lead.

Nancy Lopez, the Hall of Famer with 48 career wins who is attempting a comeback after taking most of the last four years off, was 11 over and next to last in the 143-woman field. The 50-year-old Lopez lost nearly 40 pounds in hopes of competing with players mostly half her age.

She was even through nine holes, then had three double-bogeys and five bogeys on the back side.

"It was all short game," said Lopez, who missed the cut in her only event last year. "I missed the greens and didn't get up and down, or even close. It was like stone hands for a little bit. That's been the best part of my game, so I was a little disappointed."

While Lopez was near the bottom of the leaderboard, Turner led the way for the 50-somethings on tour. Turner, who has three LPGA Tour wins but none since 1989, shot 68.

The 50-year-old player some colleagues call "Grandma" got to 6 under before a bogey-par-bogey finish.

"I know I'm the oldest player out here," Turner said. "Sometimes I know it, and I really feel it. But some days, when I play well or if I just hit one really good shot, I realize why I'm still here."

Turner contemplated retirement last year, but decided to come back for one final season.

"I look around and see all these young girls and think maybe it's time for me to move aside and let them take over," Turner said.

Ochoa appears ready to take over the spot Sorenstam has held every week since the Rolex rankings were introduced on tour in February 2006.