As usual, very little changed in the top 10. Tiger Woods, who will be looking to defend his title at the Masters this week, was the No. 1 player in the world for the 385th time.
Following Woods again were Vijay Singh, Relief Goosen, Mickelson and Ernie Els to round out the top five.
Sergio Garcia, Jim Furyk and David Toms held on to positions 6-8, while Luke Donald and Chris DiMarco moved up one spot apiece to finish the top 10.
The movement at the end of the top 10 pushed Adam Scott back two places to 11th, where he was followed by Henrik Stenson, Colin Montgomerie, David Howell and Darren Clarke.
Jose Maria Olazabal, who tied for second behind Mickelson at Sugarloaf, vaulted six places this week to No. 16 in the rankings. He was trailed by Kenny Perry, Davis Love III, Geoff Ogilvy and Chad Campbell to round out the top 20.
This edition marked the 20th anniversary of the weekly rankings. Amazingly, Woods is one of only 12 players who have ever held the No. 1 position. The others are: Bernhard Langer (three weeks), Seve Ballesteros (61 weeks), Greg Norman (331 weeks), Nick Faldo (97 weeks), Ian Woosnam (50 weeks), Fred Couples (16 weeks), Nick Price (44 weeks), Tom Lehman (one week), Els (nine weeks), David Duval (15 weeks) and Singh (32 weeks).