PHILADELPHIA -- Louis Oosthuizen parlayed his first major championship victory into a huge jump in the world rankings.
Oosthuizen cruised to a seven-stroke win at the British Open this past weekend and jumped 39 places from 54th to 15th in the world.
The top six remained the same, but there was plenty of movement behind them.
Tiger Woods held on to the top spot and was again followed by Phil Mickelson, Lee Westwood, Steve Stricker, Jim Furyk and Ernie Els.
Rory McIlroy and Paul Casey shared third behind Oosthuizen at St. Andrews and that gave both of them a two-spot bump to Nos. 7 and 8. To make room for their moves, Luke Donald and Ian Poulter both fell two places to ninth and 10th.
U.S. Open champion Graeme McDowell remained 11th and he was followed by Martin Kaymer and Anthony Kim, who exchanged places from last week. Robert Allenby held steady in 14th and he was trailed by Oosthuizen.
Retief Goosen climbed four places to 16th, while Padraig Harrington and Justin Rose fell two spots each to 17 and 18.
Sean O'Hair moved up five places to 19th, while Zach Johnson was down a pair to 20th. Camilo Villegas and Edoardo Molinari both tumbled four places out of the top 20 to 21st and 23rd, respectively.