Sorenstam, who was aiming for her third consecutive title at this event, fell short of her quest with a closing 71.
Meunier-Lebouc was steady down the stretch but stood one shot behind Sorenstam at the par-4 13th. Sorenstam had taken the lead with a birdie at the previous hole but found herself in trouble on the 13th green.
The Swede three-putted for a bogey and moments later Meunier-Lebouc drained a 16-foot putt from the fringe for a two-shot swing. Meunier-Lebouc coasted over the closing holes at even-par while Sorenstam failed to make a move and the Frenchwoman secured the victory despite a bogey at the last.
Meunier-Lebouc signed her card and took the ceremonial plunge into the pond by the 18th green of the Dinah Shore Course at Mission Hills Country Club.
Sorenstam finished one shot back, alone in second at 6-under-par 282. She led after the opening round but could not keep up with Meunier-Lebouc the remainder of the week.
LPGA Tour rookie Lorena Ochoa battled back with a 4-under 68 to finish alone in third place at 5-under-par 283. Laura Davies followed at 4-under-par 284.
Michelle Wie, the 13-year-old who played in the final group with Meunier- Lebouc and Sorenstam on Sunday, carded a 76 to finish in a tie for ninth at even-par 288.