Johnson beat Ryuji Imada in a playoff at the TPC Sugarloaf, attaining his highest-ever ranking.
Tiger Woods, of course, remained the No. 1 player in the world.
Indeed, each golfer in the top 10 retained his position from last week: Phil Mickelson was second, followed by Jim Furyk, Adam Scott, Ernie Els, Vijay Singh, Henrik Stenson, Geoff Ogilvy, Retief Goosen and Luke Donald.
Padraig Harrington moved up one place to 11th after becoming the first Irishman in 25 years to win the European Tour's Irish Open. He replaced Sergio Garcia, who slipped to 12th.
Johnson's move to No. 13 knocked Trevor Immelman and Paul Casey down one spot apiece to 14th and 15th respectively.
Rory Sabbatini, Charles Howell III, Stewart Cink, Steve Stricker and Nick O'Hern remained 16-20 in the rankings.