Harrington lost in a playoff at last year's Buick Classic and he was the runner-up the last two years at The Players Championship before finally breaking through at The Honda Classic thanks to a course record-tying 63 in the final round on the Sunrise Course at Mirasol.
Tiger Woods stayed put atop the rankings and Singh remained closely behind following his playoff loss to Harrington. Ernie Els won for the second straight week on the European Tour at the Qatar Masters on Sunday and edged even closer to Singh in the third spot.
Reigning Masters champion Phil Mickelson was fourth, while two-time U.S. Open winner Retief Goosen remained at No. 5, followed by Harrington. David Toms held onto the seventh position and Sergio Garcia dropped two spots to No. 8.
Adam Scott, Stewart Cink and Mike Weir held their spots from last week, while Stuart Appleby moved up one to No. 12. Davis Love III fell to No. 13.
Chris DiMarco, Miguel Angel Jimenez, Darren Clarke, Chad Campbell and Luke Donald all held the same positions as last week. Stephen Ames was up to No. 19 while Shigeki Maruyama advanced three spots to come in at No. 20.
Ogilvie, who was eliminated on the first playoff hole at The Honda Classic, jumped from No. 80 to No. 61 this week.