That win propelled Howell to 16th in this week's official world golf rankings. Last week, Howell, who leads the FedEx Cup points race thanks to his win and a pair of runner-ups, rose 29 spots from last week and has climbed 66 places so far in 2007.
Tiger Woods, who returns to the PGA TOUR this week for the WGC-Accenture Match Play Championship, is well ahead in first, followed by Jim Furyk.
Mickelson, trying for back-to-back wins for the third consecutive season, moved up one to No. 3. Adam Scott, the fourth No. 1 seed for the Accenture, fell to fourth, followed by Ernie Els.
Retief Goosen and Vijay Singh remained sixth and seventh, respectively. Henrik Stenson and Luke Donald switched places this week with Stenson eighth and Donald ninth. Padraig Harrington rounded out the top 10.
Geoff Ogilvy, this week's defending champion, is 11th. Sergio Garcia climbed one place to 12th, while Trevor Immelman fell one to No. 13. Paul Casey and Davis Love III stayed in 14th and 15th.
Howell was followed by England's David Howell and Nick O'Hern, who dipped two to 18th. David Toms and Colin Montgomerie each fell one to 19 and 20.