The only person she hadnt convinced was Kate Golden.
Golden fired a career-best 9-under 63 to surpass Sorenstam and win by a single shot at 21-under-par 267.
Click Here to see Kate Golden's Scorecard.
The 34-year-old native of Texas rattled off five birdies over her first nine holes, and then continued on into the latter part of the round, with four more closing birdies to claim the first-place prize of $150,000.
This is just unbelievable, said the first-time winner on the LPGA Tour after her round. I just cant believe it.
Indeed it was unbelievable.
On paper, Sorenstam looked a sure thing to grab her 30th career win. Not only was she five shots clear of the rest of the field, but she carried a record of winning on 19 occasions in 31 tries when taking a lead into the final round.
However, the likeable Swede wasnt her normally dominating self on Sunday, as she could chalk up no more than three birdies against a bogey.
She had a chance to tie the lead and force a playoff on the par-4 18th, but left her 15-foot birdie attempt out to the right to finish with a 70 at 20-under.
She did, however, win the season-culminating State Farm Bonus Series, and took home a check worth $100,000 for it.
For Golden, the win comes certainly as her finest moment in the game. In nine years on the tour, she had only been inside the top-10 on five occasions leading up to this week.
In 2001, she had missed nine cuts and not cracked the top-15 once.
Her winning check was more than $20,000 more than she earned all of last season.
I played great today, she said when it was all said-and-done.
Click Here for for Full-Field Scores from the State Farm Rail Classic.