WEST PALM BEACH, Florida -- Ai Miyazato held a one-shot lead after Thursday's opening round of the ADT Championship, the season-ending event on the LPGA Tour.

Miyazato shot a 4-under 68 at Trump International, one shot better than Chung Il-mi and two-time ADT winner Karrie Webb, one of four women in the field still alive in the tour's money title race.

"It was a great round ... because I kept my concentration today," said Miyazato, who has six top-10 finishes but no wins this season. "I had fun playing in the strong wind. That was fun."

Natalie Gulbis, Kim Mi-hyun and Julieta Granada were each two shots off the pace at 2 under, while four other players - Wendy Ward, Morgan Pressel, Se Ri Pak and Paula Creamer - were another stroke back.

"I was a little brain-dead," Pressel said. "The day was OK, overall. I certainly made enough birdies out there to be right in the hunt, but I gave too many shots away."

Meanwhile, two-time defending ADT champion Annika Sorenstam and newly crowned player of the year Lorena Ochoa both struggled.

Sorenstam was 4-over after 10 holes before rallying to finish 2-over, six shots off Miyazato's lead. And Ochoa was 3-over in her opening round, with four bogeys and only one birdie.

"It just wasn't a good day," Sorenstam said. "I got off to a bad start. I had to fight pretty hard today."

The 32-woman field gets cut to 16 Friday, then eight Saturday - with those players returning Sunday, their scores from the first three days erased, to play for the $1 million winners' share of a $1.55 million purse. It's the largest first prize in LPGA Tour history.

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