Els, who won for the 14th time on the PGA Tour, supplanted Vijay Singh as the second-ranked golfer in the world. Singh, who had moved into second last October, dropped one spot to No. 3.
Tiger Woods finished third at Muirfield Village and maintained his No. 1 ranking by a 2.28-point margin over Els.
Davis Love III held onto fourth followed by Phil Mickelson, Mike Weir, Jim Furyk and Padraig Harrington, all of whom remained unchanged in the rankings. Retief Goosen moved up one spot to No. 9, while Chad Campbell fell one position to round out the top 10.
Stuart Appleby, Kenny Perry, Darren Clarke, Adam Scott, David Toms, Scott Verplank and Sergio Garcia stayed put in the 11-17 spots. K.J. Choi climbed two spaces to No. 18 followed by Fred Couples, who vaulted 18 positions to No. 19 in the world after his runner-up finish at The Memorial Tournament.
Jonathan Kaye, who will defend his title this week at the Buick Classic, dropped two spots to No. 20.
There was another surprise winner on the European Tour as Simon Khan came back to upset Paul Casey in a playoff at The Celtic Manor Resort Wales Open. With the victory, Khan improved 114 spaces to No. 141. Casey, meanwhile, jumped up three positions to No. 27.