Garcia, who also won the Byron Nelson earlier this season in a playoff, won for the fifth time on the PGA Tour. Garcia returned to the top 10 for the first time since March of 2003.
Tiger Woods, who will take on Shinnecock Hills in his quest for a third U.S. Open title this week, remained in the top spot in the ranking but his advantage over Ernie Els has shrunk inside the two-point range.
Vijay Singh continues to lurk right behind Els in the third spot. A trio of major champions in Davis Love III, Phil Mickelson and Mike Weir followed, all of whom held their rankings from last week.
Harrington, who will try to end the European drought at the U.S. Open, moved up one position to No. 7. Jim Furyk, still recovering from wrist surgery but committed to defending his title this week at Shinnecock, dropped one to No. 8. Retief Goosen, the 2001 U.S. Open champion, stayed put at No. 9 while Garcia followed to round out the top 10.
Chad Campbell fell one space to No. 11 while Kenny Perry held on to the 12th spot. Stuart Appleby dropped two positions to No. 13 and Darren Clarke moved one spot downward to No. 14.
Adam Scott and David Toms each fell one spot to come in at 15th and 16th, respectively. Fred Couples, who held the 36-hole lead at the Buick Classic, moved up two rungs to No. 17. Scott Verplank dropped two spaces to No. 18 while K.J. Choi fell one to come in at the 19th spot.
Jay Haas climbed one position to complete the top 20.
Miles Tunnicliff, who earned his second career victory on the European Tour in dominating fashion at the Diageo Championship at Gleneagles last week, vaulted up 110 positions to No. 151.