A formidable foursome stand together at five-under 139, including defending champion Karrie Webb, who shot a three-under 69.
Webb defeated Sorenstam on the first playoff hole for the title at the inaugural playing of this tournament last year. It was her third win in three starts to begin the 2000 season, and she went on to become the first player since 1990 to win seven times in a year.
Webb is winless in three events this season, with back-to-back runner-up finishes in her last two starts.
Webb had a chance to share the second-round lead with Sorenstam but missed a 40-foot eagle try at the final green. She then lost her bid for sole possession of second place with a two-putt from 10 feet.
Her only two bogeys Friday came on misses from around the same range. Webb was short with her approach at the opening hole then failed to get up and down after chipping to 12 feet. At the par-four 13th, Webb put her second shot in a greenside bunker then needed two putts after blasting out to 10 feet.
Webb did manage to make five birdies, among them a 20-foot putt set up by a five-iron from the tee at the 172-yard third hole.
'I'm putting well and hitting the ball well, I just seem to be throwing one bad swing in there and making bogey, so I lose my momentum,' said Webb, who had birdies at 11 and 12 before the mistake at 13. 'It seems like when you shoot a really low score, you don't make silly bogeys like that.'
In 23 LPGA victories, Webb has come from behind to win 10 times.
Sorenstam, who is playing in her first event of the 2001 season, was tied with Webb, three back of first-round leader Maria Hjorth at the start of round two.
After a solid front side that saw her notch birdies with putts from 10 and 13 feet, Sorenstam really came to life on the inward nine with three birdies over the first four holes.
'Overall, I'm very happy with the way I played today, and to tell you the truth, with yesterday too,' said Sorenstam, who had a 70 in her opening round of the year. 'For the first round out, I was a little rusty and made some mistakes at the end. But I cleaned it up a little bit. No mistakes today and five birdies, that's a solid round of golf.'
Sorenstam, who also had a two-stroke advantage over Webb after 36 holes a year ago, said she won't dwell on her sudden-death defeat at the hands of the young Australian.
'To be honest, I have quite a bad memory of certain things,' said the 30-year-old Swede. 'I remember I was leading, but that's all. I know I'm happy with how I'm playing now. For my first week, I couldn't have asked to feel better about my game.'
Of the 28 times that Sorenstam has taken the lead into the final round, she has gone on to win 16 times, placed second four times, third six times and finished sixth twice.
Sorenstam is coming off a five-win season in which she finished second to Webb in earnings with over $1.4 million.
Lorie Kane, who had a breakthrough year in 2000 with three victories, also posted a 69 Friday to get to five-under, as did Cristie Kerr, who finished second twice last season.
A.J. Eathorne joined the group in second with a 70.
Among the players who rounded out the top-10 at four-under were Pat Hurst, Dorothy Delasin and Sophie Gustafson, each of whom earned victories in 2000.
Gustafson also won the Memorial of Naples event last month.
Hjorth, who shot a 67 for the lead after one round, fell into a tie for 17th with a second-round 75.