Singh is within 3.1 points of Tiger Woods' lead, the closest anyone has been since 2001. Woods has been on top of the rankings for 235 consecutive weeks.
Ernie Els held on to win the Heineken Classic by a single shot on the European Tour this week. He remained in third place, followed by Davis Love III, reigning U.S. Open champion Jim Furyk, Masters winner Mike Weir and Retief Goosen.
Kenny Perry moved up one place to eighth, while Phil Mickelson, who finished third at Pebble Beach, returned to the top-10 at No. 9. David Toms fell two to 10th.
Ireland's Padraig Harrington dropped one to 11th, while Darren Clarke, Stuart Appleby, Jonathan Kaye and Nick Price stayed in their spots from last week and completed the top-15.
Chad Campbell held on to the 16th spot, followed by Robert Allenby, Fredrik Jacobson, Thomas Bjorn and Justin Leonard.