DiMarco, a University of Florida graduate with one of the tour's most unorthodox putting grips, claimed his first victory at last year's SEI Pennsylvania Classic. He continued his rise this season with nine top-10 finishes, including two third-place showings, a second and a win in his last nine starts.
The top six players held their positions from last week, with No. 1 Tiger Woods still holding a big lead over No. 2 Phil Mickelson in the points-based rankings. Mickelson, whose wife, Amy, gave birth to the couple's second child last week, has opted to stay close to home and won't defend his title in the season-ending Tour Championship this week.
Duval, the reigning British Open champion, remained third followed by Davis Love III, Ernie Els and Vijay Singh.
PGA Championship winner David Toms moved up to seventh place in an exchange of positions with Sergio Garcia. Toms has two other victories this season and with a win in the Tour Championship, may have a shot to unseat Woods for the PGA Tour Player of the Year Award, which is voted on by the tour's membership.
Although Northern Ireland's Darren Clarke was ranked ninth in the world, one spot ahead of Retief Goosen, he is currently second to the U.S. Open-winning South African in the European Tour's Order of Merit. Goosen, who moved from 13th to 10th this week, locked up the top spot on Europe's 2001 money list with a victory, his third of the season, at the Open de Madrid on Sunday.
Colin Montgomerie, Scott Verplank and Bernhard Langer each dropped one slot to 11th, 12th and 13th, respectively, to accommodate Goosen's rise.
There was no movement with the players ranked 14th through 18th. Jim Furyk and Padraig Harrington of Ireland were followed by Argentina's Jose Coceres, who had a big breakthrough season on the PGA Tour with victories in the Worldcom Classic at Harbour Town and the National Car Rental Golf Classic at Walt Disney World.
Scott Hoch, another two-time winner this year, stayed 17th, one spot ahead of Canadian lefthander Mike Weir. DiMarco and Bob Estes rounded out the top-20.
Estes, who ended a seven-year drought with a win at the St. Jude Classic in June, placed in the top-10 in each of his last five starts, adding a second 2001 title at the Invensys Classic at Las Vegas.
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