Luke Donald and Lee Westwood remained the top-two ranked players. Martin Kaymer finished second at the European Masters and improved two spots to No. 3, while Rory McIlroy shared third at Crans-sur-Sierre and moved up a pair to No. 4.
Simpson moved into 14, Bubba Watson stayed put at 15 and K.J. Choi slipped two to 16th. David Toms, Ian Poulter, Paul Casey and Robert Karlsson -- who all dipped a notch -- rounded out the top 20. Kyung-tae Kim fell one to 21st to drop out of the top-20.
Thomas Bjorn won his second straight European Tour event and soared 31 places to No. 28 this week.