Webb's victory was her fifth of the season, equalling Lorena Ochoa's haul for the season, and it moved her into second place behind the Mexican in the money list on $2,069,613.
"It's an unbelievable feat to win a tournament five years in a row," said Webb, who earned $180,000 for her 35th career title.
"You can't take anything away from Annika. You don't go out there trying to beat someone. I just wanted to make as many birdies as possible. It was very close at the turn but I had a fantastic back nine."
Sorenstam was less than pleased after a closing 70 gave her a three-round total of 207. "I'm feeling a little disappointed about the way I played," she said. "I couldn't get anything going at all."