Dustin Johnson's first reign at No. 1 in the Official World Golf Ranking ended after the 2018 Players Championship, when Justin Thomas became the 21st player to become No. 1 in the world.
Johnson didn't finish highly enough at TPC Sawgrass, while Thomas did what was required to take over the top spot in the world ranking. It's the first change since Johnson took over the world No. 1 ranking after winning at the 2017 Genesis Open.
The world No. 1 ranking will have changed hands 69 times, when Thomas retakes No. 1 on Sunday, since the ranking debuted before the 1986 Masters. There have been 13 reigns of just one week:
Seve Ballesteros (2) -- 11/22/87 -- to Greg Norman
Seve Ballesteros (3) -- 10/30/88 -- to Greg Norman
Greg Norman (3) -- 11/6/88 -- to Seve Ballesteros
Greg Norman (4) -- 3/26/89 -- to Seve Ballesteros
Fred Couples -- 3/22/92 -- to Nick Faldo
Nick Faldo (3) -- 3/29/92 -- to Fred Couples
Tom Lehman -- 4/20/97 -- to Greg Norman
Tiger Woods -- 6/15/97 -- to Ernie Els
Ernie Els -- 6/22/97 -- to Greg Norman
Greg Norman (10) -- 6/29/97 -- to Tiger Woods
Tiger Woods (4) -- 5/10/98 -- to Ernie Els
David Duval (2) -- 8/8/99 -- to Tiger Woods
Luke Donald (3) -- 4/29/12 -- to Rory McIlroy
On the other side of the coin, there have been eight reigns at No. 1 that have lasted longer than a year:
Tiger Woods (10) -- 6/12/05 to 10/30/10 -- 281 weeks
Tiger Woods (7) -- 8/15/99 to 9/4/04 -- 264 weeks
Greg Norman (8) -- 6/18/95 to 4/19/97 -- 96 weeks
Nick Faldo (4) -- 7/19/92 to 2/5/94 -- 81 weeks
Dustin Johnson (1) -- 2/19/17 to 5/13/18 -- 64 weeks
Greg Norman -- 9/14/86 to 11/21/87 -- 62 weeks
Tiger Woods (11) -- 3/25/13 to 5/17/14 -- 60 weeks
Greg Norman (5) -- 8/20/89 to 9/1/90 -- 54 weeks
Rory McIlroy (5) -- 8/3/14 to 8/15/15 -- 54 weeks
A total of 21 players, including Spieth, have held the No. 1 ranking, and Lehman is the only one to have held it for just one week in his career.