Hamilton, a 38-year-old PGA Tour rookie who played several years in Japan, birdied his final two holes Sunday on the Sunrise Course at Country Club of Mirasol to edge Davis Love III by a single shot.
Tiger Woods, who will take aim at a fifth consecutive Bay Hill title this week, remained firmly atop the rankings. He was followed by Vijay Singh, Ernie Els, Love and Mike Weir, all of whom held their positions from last week.
Reigning U.S. Open champion Jim Furyk held onto the sixth spot, while Retief Goosen, Phil Mickelson, Stuart Appleby and David Toms all stayed put to round out the top-10.
There was no movement in the next five spots either as Kenny Perry, Padraig Harrington, Darren Clarke, Jonathan Kaye and Chad Campbell held down the fort from 11-15.
Fredrik Jacobson moved up three spots to No. 16, while Scott Verplank dropped one position to No. 17.
Robert Allenby climbed two spaces to come in at No. 18 this week, followed by Nick Price, who fell two spots to No. 19. Chris DiMarco also dropped two to round out the top-20.
Joakim Haeggman, who captured the European Tour's Qatar Masters last week, jumped 100 spots to No. 123.
Current World Rankings