Ahead by five strokes after a third-round 66, Webb parred the final five holes Sunday for a 2-under 70 and one-stroke victory over Sorenstam, the Swedish star who made things interesting with a 65.
Webb won her LPGA Tour-leading fourth title of the year and pushed her career total to 34 -- 35 if you count her win in the 1995 Women's British Open before she became an LPGA Tour member. The resurgent Australian star, inducted into the Hall of Fame last year, had a 15-under 273 total on Blackhawk Country Club's hilly Lakeside Course. She earned $165,000 to remain second on the money list with $1,873,753.
While Webb dropped two strokes on the 155-yard, par-3 seventh after hitting her tee shot into a lake, Sorenstam was making a move in the threesome ahead of her. By the time Sorenstam made a long eagle putt on the par-5 ninth, Webb's lead was down to two.
Sorenstam added birdies on Nos. 15 and 17 to cut Webb's lead to a stroke. Sorenstam had a chance to make it even more interesting at No. 18, but her approach over the lake went long and into the back rough. She missed the chip and settled for par.
Eighteen-year-old Morgan Pressel (68) finished third at 12 under, and Lorena Ochoa (66), Cristie Kerr (68), Mi Hyun Kim (69) and Stacy Prammanasudh (68) followed at 10 under. Ochoa, 4 under at the start of the round, was 11 under at one point.
Pressel vowed a day earlier to shoot at the flags and try to make an early run at Webb. Instead, Pressel shot even par on the front nine, never quite seeming to find the right speed for her birdie putts and running several of them well by the hole.
Winless last year, Webb broke a tie with Sorenstam, Ochoa and Kerr for the tour victory lead with four. Webb won the Kraft Nabisco Championship for her seventh major title and also won the Michelob Ultra Open and Evian Masters.
Webb's tee shot on the seventh came up well short and fell into a lake guarding the front right of the green. She took a double bogey there and could only stand and listen as the loud roars grew more frequent ahead of her as Sorenstam began to pour in birdies on the front nine and eagled No. 9. But Webb rebounded with birdies on Nos. 11 and 13 and closed with the five straight pars to hang on.