The LPGA heads into an Asian swing with tournaments in South Korea, Malaysia and Taiwan this month as the 2011 schedule begins to wind down.
Choi moved past South Korean countrywoman Shin Jiyai for fourth in this week's world rankings. Lewis, also switching places with a compatriot, is ninth, pushing Brittany Lincicome of the United States to 10th.
Yani Tseng has a commanding hold on the world No. 1 ranking with a points average of 16.75. No. 2-ranked Suzann Pettersen (11.93) and Cristie Kerr, in third at 11.68, are close while Choi comes in fourth at 9.02 and Shin (8.76) is fifth.
Ahn Sun-ju remains sixth at 7.99 while Aiu Miyazato (7.66) is seventh and Paula Creams (7.55) is again eighth. Lewis's average is 7.32 , just ahead of Lincicome at 7.27.