Pettersen finished tied with Choi No-yeon for third in last week's Avnet LPGA Classic in Alabama. She was three strokes behind Maria Hjorth, who jumped from 27th to 16th in the rankings. Kim Song-hee was second and improved two places to 11th.
Four Top 10 players, including No. 1 Yani Tseng and second-ranked Jiyai Shin, failed to make the cut at the Avent and Cristie Kerr tied for 23rd, which drops her from third to fifth, changing places with Pettersen.
Tseng has a ranking points average of 11.78 and Shin is at 9.89. Pettersen's average is 9.01, not far ahead of Choi (8.97) and Kerr (8.84).
Kim In-kyung (7.63) is sixth, trading spots with Ai Miyazato (7.57), who was among those who missed the cut. Karrie Webb (6.94) remains eighth and Michelle Wie (6.77), the fourth Top 10 player to have missed the cut, is ninth.
Inbee Park (6.24) moves to 10th but with same average as Kim Song-hee and Paula Creamer. Park, however, has played in more tournaments so is given the higher ranking.