Defending champion Annika Sorenstam posted a 3-under-par 69 and is tied for third place with Catherine Cartwright, Jimin Kang, Jamie Hullett, Meena Lee and Laurie Rinker.
Sorenstam began on the back nine at Corning Country Club and tallied a pair of bogeys in her first four holes. She reclaimed the lost strokes with a 7-foot eagle putt at the par-5 14th.
The Swede recorded three birdies in a row from the 15th, and all three putts were inside 6 feet. Sorenstam collected her second eagle of the round at the second when her 9-iron stopped 8 feet from the hole.
Sorenstam picked up a pair of three-putt bogeys at five and seven and the No. 1 player in the game realized Thursday was a tale of two different rounds.
'It was a little bit up and down today for sure, but I'm glad I had a good stretch in the middle,' said Sorenstam. 'I'm very happy with the way I played six or seven holes. I was like seven-under. I'll take that. But then I didn't start as well, and then I didn't finish as well as I'd like to. I have a few things to work on.'
Gustafson wasted little time in breaking into red figures as she birdied the par-5 second. She ran off back-to-back birdies at five and six, but dropped a shot at the ninth when her 9-iron approach sailed right of the green and she missed her 12-foot par save.
At the 11th, Gustafson mishit another 9-iron and left with another bogey. She made up for it with back-to-back birdies at 12 and 13 before parring the 14th.
Gustafson surged up the leaderboard in the end of her round. She hit a wedge to 5 feet to set up birdie at the 15th, sank a 10-footer for birdie at 16 and closed with a birdie at 17.
'I played good. I was excited about this week,' said Gustafson. 'Even though the course is short, I was going to play aggressive. I hit a lot of drivers, so I didn't really have very far for my second shot.'
Turner, who missed most of last season after shoulder surgery, drained a 35- foot eagle putt at the second. She sank a 15-foot birdie putt at five, then picked up consecutive birdies from the eighth.
Turner, who won the 1988 LPGA Championship, added another birdie at the 11th, but dropped a shot at 15. She came up short of the green and three-putted, but atoned for the mistake with a tap-in birdie at the 16th.
'I'm not going to say I'm totally surprised I played this well today,' said Turner. 'It's been a long time. I just felt really peaceful and really at ease out there today.'
Joanne Mills, Jen Hanna, Kate Golden, Sung Ah Yim, Ji Yeon Lee, Karine Icher and Moira Dunn are knotted in ninth place at 2-under-par 70.