She played solidly for an even-par 71 in the morning to keep a share of the lead, then spent the afternoon resting in her palatial quarters as Pat Hurst, Michelle Wie and the rest of her challengers battled the blustery conditions at Newport Country Club, knowing they would have a short night before the marathon finish.
They'll need plenty of rest for the 36-hole Sunday, the first in 16 years at the U.S. Women's Open.
Sorenstam was in the best shape of all -- physically, for sure -- by finishing her round about 1 p.m. at 2-under 140. Hurst had consecutive bogeys in the middle of her round, then steadied herself with a birdie on the par-5 16th for a 71 to tie for the lead.
One shot behind was a group that included Wie and her wild day.
Tied for the lead, Wie took two shots to get out of a muddy bunker and made double bogey on the 17th hole. In danger of falling farther behind, the 16-year-old from Hawaii escaped with an amazing par on No. 7 by taking an unplayable lie from the shrubs, blasting an 8-iron out of the muck and over a ravine to within 10 feet, and making the putt.
'It was all in all a very good hole,' she said. 'Right after it went in the hole, I laughed at myself. It was pretty ridiculous.'
Wie wound up with a hard-earned 72 and was at even-par 142, along with 19-year-old amateur Jane Park (73) and Shi Hyun Ahn (71). Inkster, a two-time Women's Open champion, was another shot back at 143 in a group that included five-time major champion Se Ri Pak (74) and 19-year-old Paula Creamer (72).
All of them face a brutal challenge Sunday.
The pressure in the final round already is enormous at the U.S. Women's Open, by far the biggest championship on the LPGA Tour. But they first have to play 18 holes to get there, making for a 10-hour day on a course that is relentless.
'It's going to be a grind,' Inkster said. 'You've just got to hang tough and try not to blow a gasket out there.'
Dense fog that wiped out Thursday's first round is the culprit for the first 36-hole Sunday at the Women's Open since 1990, and what happened that day is a reminder that this tournament is far from over. Betsy King overcame an 11-shot deficit at Atlanta Athletic Club to overcome fast-fading Patty Sheehan.
Even with Sorenstam atop the leaderboard, looking determined to end her 10-year drought in the Women's Open, this tournament is still up for grabs. There were 18 players within five shots of the lead with 36 holes to play.
'Today is normally moving day,' Creamer said. 'Tomorrow, we're just going to have to keep it going.'
Sorenstam played another tidy round in mild breezes, opening with 13 consecutive pars until she hit a 4-iron to 15 feet on the par-3 fifth. It was back-and-forth from there, a 7-wood that didn't reach the sixth green for bogey, a 15-foot birdie putt on the seventh that hung briefly on the edge of the cup before falling, and a bogey on the ninth when 7-wood from the rough came up short.
'It's going to be a long day tomorrow, and I think the key for me now is to get some lunch and rest, and totally recharge my batteries, and give it my all tomorrow,' she said.
Most of the women have experience with 36 holes, having played in the Solheim Cup, or in the case of players like Wie or Park, competing in various U.S. Amateur events.
But those weren't held on such a demanding course as Newport.
'I'm tired after 71 shots,' Sorenstam said. 'Tomorrow is going to be probably double that, and that takes a lot out of you.'
For Wie, it was all she could do to hang on in the second round.
Her confidence was high after saving par with an 8-foot putt on the 10th hole, making a 15-foot birdie on the 12th, and bouncing back from a bogey on the 15th by nearly reaching the 549-yard 16th in two shots.
Then came a 6-iron that leaked into a bunker, settling in a large puddle from so much rain earlier in the week. After dropping in mud-caked sand, she tried to get it close to the hole and didn't get out of the sand, fortunate to escape after that with double bogey.
Nothing quite topped the par at No. 7.
First came a fairway metal that hooked so badly, Wie hit a provisional in case it was lost. She found the original, and took a one-shot penalty for two club lengths of relief, although that was no bargain.
'I saw the area where I was going to drop it and said, 'Oh, great. I'm either going to be in the weeds or I'm going to be in a mud patch.' I tried to land it on a piece of grass.'
She missed, and it sat in the muck of trampled weeds. Taking her right hand off the club at impact, she hammered an 8-iron from 140 yards and it came out perfectly, and the par putts might have been her most important shot.
Wie has been a factor on Sunday in the last five majors, and her putting stroke was far improved than three weeks ago at the LPGA Championship, when she took a dozen more putts than Pak in finishing two shots out of the playoff.
'It's going to be the first time playing 36 holes in the U.S. Open,' she said. 'It's going to be a fun ride, playing 36 holes in one day. I'm not going to take it too seriously, try not to pump myself up too early. Play hole by hole, and eventually it will add up to 36.'
It only it were that simple.
King's victory in Atlanta showed that momentum can change quickly, and even a deficit that reaches double digits is no reason to lose hope. Throw in a U.S. Open course, and Sunday will be a matter of who can survive.
'Thirty-six holes on another golf course would be no problem,' Inkster said. 'Out here, you're going to have to hit the ball solid.'
Inkster was reminded of the strange week when she finished her 18th hole, traded hugs with her playing partners and said what she always does after the second round of a tournament -- good luck on the weekend.
Then she caught herself.
'Have a good day tomorrow,' she said.