Steinhauer, the last of the 10 automatic qualifiers for the U.S. team for the Sept. 14-16 matches against Europe in Sweden, had five birdies in her bogey-free round on the Panther Creek Country Club course. Winless since the 2006 Women's British Open, Steinhauer played alongside Solheim Cup teammate Angela Stanford (72).
'I think we do consider ourselves teammates out there and we're pulling for each other ... And we were talking about some things with Solheim out there today, and we're just really looking forward to the competition,' said the 44-year-old Steinhauer, making her 20th appearance in the tournament.
Sorenstam, the winner last year at the Rail Golf Club, had two birdies and a bogey in a round of 71. On Saturday, Sorenstam announced that she's marrying Mike McGee, her boyfriend of two years. It will be the second marriage for the 36-year-old Swede, who filed for divorce from David Esch in February 2005.
'I think I played really well today,' Sorenstam said. 'I hit 16 greens and didn't miss any fairways, so I think I played very, very solid. I had a lot of chances and had a lot of looks out there. If that is any indication of how I'm going to play the next few months I'm happy about it. I'm just going to go out there tomorrow and continue what I'm doing and hopefully it works out.'
Last season at Rail, Sorenstam won the last of her 69 LPGA Tour titles, closing with a 10-under 62 to match the lowest final-round score by a tournament winner in tour history. The tournament moved to Panther Creek this year after 31 seasons at Rail.
'I thought today was tougher than the practice round and the pro-am,' Sorenstam said. 'The wind picked up and the ball traveled to different places. The greens are getting firmer and the fairway is getting firmer.'
Japanese star Ai Miyazato and Marcy Hart opened with 68s.
'It was very windy today,' Miyazato said. 'I just tried to make one shot at a time. I had good concentration today, so I feel very satisfied.'
Kraft Nabisco champion Morgan Pressel shot a 69. The 19-year-old Pressel closed with a double-bogey 6 on No. 9 after hitting into the water.
'It is only Thursday, but those two shots could cost me just as much as two shots on Sunday,' Pressel said. 'I wish it hadn't happened, but it has so I have to go make a few more birdies.'
Christina Kim, Kate Golden, Angela Park, Rachel Hetherington, Janice Moodie and Leta Lindley also shot 69s, while Sophie Gustafson and Women's World Match Play winner Seon Hwa Lee topped a large group at 70.
Golden, the 2001 winner, said she'll have to rethink her prediction of an 18 under winning score if the wind stay up.
'The wind really affects the balls, and as firm as the fairways and around the greens are getting, it will be tough unless you're really firing at the pin. And that is kind of tough to do in the wind,' Golden said.
Steinhauer made four long birdie putts -- a 30-footer, 25-footer and two 20-footers -- and hit a 6-iron shot to 3 feet to set up another birdie on the par-5 16th.
'It was one of those days where I just kind of got them started on line, and they held their line,' said Steinhauer, whose seven career wins include two majors. 'And that's generally due to, you know, striking it solidly, the putts. And I was doing that today, and not something I've been doing much this year, so it felt really good.'
Nancy Lopez, the 50-year-old star making her sixth tour start of the year, shot an 81. She won the tournament in 1980 and 1992.
Top-ranked Lorena Ochoa is skipping the tournament after winning three straight events to push her tour-leading total to six.