Oosthuizen lost Sunday on the third hole of a sudden-death playoff to an eagle by Matteo Manassero at the European Tour's Barclays Singapore Open but still moves from 10th to No. 6 in the rankings.
Scott was fifth in the same tournament and inches up from sixth to fifth.
Manassero improves his ranking 39 places to No. 46 but the big move of the week belongs to Charlie Beljan, who collected his first professional win Sunday at the PGA's Children's Miracle Network Classic in Florida. That rockets Beljan from 351st to No. 159 in the rankings.
The top of the rankings remains the same with Rory McIlroy, who wound up third in Singapore, No. 1 with a rankings points average of 13.014. Tigers Wood, with an average of 9.119, is second followed by Luke Donald (8.774) and Lee Westwood (6.715).
Scott comes in with an average of 6.235 and Oosthuizen is at 6.211. Justin Rose, down two places to seventh, has an average of 6.170, with Jason Dufner, in eighth after dropping one spot, at 5.909. Brandt Snedeker (5.702) remains ninth and Webb Simpson, eighth last week, is No. 10 at 5.699