Feng wound up in a tie for 27th at the LPGA's Mizuno Classic in Japan, which dropped her rankings points average to 7.88. Pettersen, who didn't play in the Mizuno Classic, has an average of 7.98.
Choi Na-yeon is third in the rankings with an average of 8.43, tightly followed by Inbee Park at 8.36.
After Pettersen and Feng comes No. 7 Jiyai Shin, whose average is 7.45 while Ai Miyazato is eighth at 7.09. Ryu So-yeon has the ninth-best average at 6.64 and Mika Miyazato (6.29) has the No. 10 spot.
The LPGA has two events remaining on its 2012 calendar, including this week's Lorena Ochoa Invitational in Mexico and the Nov. 15-18 CME Group Titleholders tournament in Naples, Fla.