SINGAPORE — Lorena Ochoa says she's geared up for a "battle" to keep her top ranking in her first LPGA Tour tournament of the season when she tees off Thursday in the inaugural HSBC Women's Champions.

Former world No. 1 Annika Sorenstam hopes the momentum from a drought-breaking win at the SBS Open earlier this month in Hawai'i will help in her quest to reclaim the LPGA top spot.

Mexico's Ochoa skipped Hawai'i, where Sorenstam claimed a two-stroke victory in the season-opening SBS Open and finished fourth at the Fields Open the following week.

"I was at the beach while Annika was winning — at the beach too," Ochoa joked Tuesday. "I didn't play the first two tournaments because I needed to spend a little more time at home and get prepared and be more ready.

"I feel ready. I think this is going to be a great year for all of us. We all want to finish at the first place, so let's start with a battle," she said.

With a $2 million purse and $300,000 top prize, the HSBC Women's Champions will be the richest women's golf event in Asia.

Ochoa will have plenty of competition at Singapore's Tanah Merah Country Club, most notably Sorenstam, whose SBS Open victory vaulted her two spots to No. 2 in the world.

Coming off an injury-shortened season in 2007, where the Swedish star was winless on the U.S. LPGA Tour for the first time since her rookie season in 1994, Sorenstam was relieved to claim her 70th title to start 2008.

"There's definitely a spring in (my) step," Sorenstam said. "I feel good again, I'm working out hard and I'm playing and practicing as hard as I can, so I feel healthy and I'm excited about the year."

Sorenstam acknowledged that it would not be easy surpassing Ochoa, who leads by a large margin after an impressive eight wins in 2007. Sorenstam was limited to 13 events last year because of neck and back injuries.

"Of course I would love to do that," she said when asked about regaining her top ranking. "I do think it's going to take a lot for me this year to do that ... I have a lot of catching up to do, so I'm just going to take one step at a time."