Miyazato took advantage of a collapse by second-round leader Veronica Felibert to collect her second title of the season and ninth of her LPGA career.
Miyazato finished at 12-under-par 201 at Pinnacle Country Club, one shot better than Azahara Munoz (65) and Mike Miyazato (67) at minus-11.
Felibert, who led by four shots after the first two rounds, fell to a 1-over 72 and dropped into a tie with Inbee Park (68) for fourth place at 10-under 203.
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