Shrugging off gusting wind, heavy rain and a weather delay, the 20-year-old Miyazato rebounded from an early bogey with six birdies to finish the second round at 10-under 132. Sorenstam followed her opening 64 with a 69.
Miyazato, who grew up idolizing Sorenstam, played an awful lot like her on the rain-soaked Seaview Resort & Spa course. After missing a 10-foot putt for par at No. 2, she was error-free the rest of the way.
She birdied the next two holes and then connected on a 20-foot putt to pick up another stroke on the 182-yard, par-3 seventh hole.
She birdied Nos. 12 and 16 and was about to finish her round when a rain delay was called -- with her ball sitting a foot from the cup at No. 18.
Fifty-two minutes and one hamburger later, she made the birdie putt.
'She's incredible,' Diaz said.
Miyazato started the round determined not to let recent history repeat itself.
'Yesterday, I lost some shots on the last three holes,' she said through a translator. 'So today I just tried to make sure I stay concentrated and not do the same thing.'
She said she'll be nervous teeing it up Sunday with the LPGA Tour's marquee player.
'She is my idol. She has been my idol and she is a player that I admired and someone I look up to all the time,' said Miyazato, whose best previous finish on tour was a tie for fifth.
Miyazato, who won six tournaments in Japan last year, won the LPGA Tour qualifying tournament by 12 strokes last November to earn her exempt card for the 2006 season. She played in six tour events last year, her best finish a tie for ninth in the HSBC Women's World Match Play Championship.
Sorenstam, who started the day tied for the lead with Michele Redman, struggled with her putter early on, missing several birdie opportunities and carding three bogeys in her first eight holes.
But just as she did Friday, she rallied midway through her round, making shots that were vintage Sorenstam. She made a 4-footer for birdie on the ninth, then dropped a blind approach shot 3 feet from the cup and made the putt at No. 10.
On the 11th, she holed a 29-foot chip shot from the front fringe for another birdie, taking back a share of the lead at 9 under. But she shot par the rest of the way to set the scene for a potential repeat of the 2005 Classic victory.
She has won this event three times.
'I'm in position to do some good things tomorrow and I'm obviously ready for that,' Sorenstam said. 'I've been waiting for it. It's been kind of a dry two months for me.'
Sorenstam, who has 67 career LPGA Tour wins, has won only once on tour this year. She is winless in her last six outings and seventh on the money list.
Weather could play a big role in the final round, she said.
'If it's windy, it makes this golf course a totally different golf course,' she said. 'The greens are going to be softer. We can be a little more aggressive with our approach shots.'
Steinhauer surged into contention with her 66, tying her with Diaz, who also managed a solid round of 69 despite suffering from a cold caught while tending to her 4 1/2 -month-old son.