Miyazato won the tournament -- her fifth LPGA title of the year -- by two strokes over Choi No-yeon and Cristie Kerr with Kim Song-hee and Suzann Pettersen tied for fourth another stroke back. Miyazato turned in an even-par 72 Sunday and finished the 54-hole tournament at 11-under 205.
Her move to the top of the rankings marks the third time Miyazato, who leads the LPGA money list and the standings for 2010 Player of the Year, has taken over the No. 1 ranking. Her two previous visits each lasted just one week, however.
She knocked Kerr, who moved to No. 1 last week, to second in the rankings. Pettersen moved up one spot to third while Jiyai Shin, No. 1 two weeks ago, slipped to fourth after tying for sixth at the Safeway Classic.
Seven of last week's Top 10 golfers finished at least tied for sixth at the Safeway Classic. Yani Tseng, despite a tie for 45th, held onto the No. 5 spot while Choi remained in sixth.
Kim went from 10th to seventh, knocking three golfers each down one spot. Paula Creamer dropped to eighth and Kim In-kyung, who tied Shin for sixth in Oregon, fell to ninth, and Anna Nordqvist is 10th.