The 30-year-old Swede shot 67 on Day 3 to move to 18-under-par, and will take a five-stroke lead into the final round over Kristie Kerr, who recorded a career-best 63 at the par-72 Rail Course.
As good as the 23-year-olds score was, however, Sorenstam is light-years ahead of her on the leaderboard.
The six-time winner in 2001 was not quite as perfect as she had been in the first two rounds, but made up for it in the end.
Sorenstam headed into the par-4 17th having just recorded her third bogey of the round, but reacted by hitting an approach to four-feet and sinking the birdie, and then making another birdie inside of ten-feet on the closing 18th.
In all, her three blemishes on the day were offset by eight red numbers.
The birdie on 18 was great, said a smiling Sorenstam after the round. Its a good way to finish, and being 18-under is obviously better than being 17-under.
Her opponents might not think so.
A Sorenstam-victory on Sunday would be the 30th of her career. Her number of seven wins on the season would mark a personal best.
If trends mean anything, the odds are that she will get that seventh.
In 31 times that Sorenstam has taken the lead into the final round of an LPGA event, she has won 19 times.
Its no different than on the PGA Tour with Tiger (Woods) psyching people out, observed Emilee Klein, who is tied for third with four others at 12-under heading into Sunday.
You have to have enough confidence in your game to know that if you play good enough, youll do it.
Sorenstam apparently understands that reality like no one else.
She wasnt even necessarily satisfied with her round on Day 3.
It was one of those days where you had to work pretty hard, she said.
Thing is, it never really appears so.
*Sorenstam is looking to bag not just the $150,000 first-place prize for the tournament, but also an additional $100,000 should she win the State Farm Series competition which ends on Sunday.
For the year, she has a 100-point lead over everyone. Three hundred points are on the table this week.
Click Here for for Full-Field Scores from the State Farm Rail Classic.