Day moved to No. 1 after his six-shot win at Conway Farms, marking the first time the Aussie has topped the Official World Golf Ranking. This was Day's fourth win in his last six starts dating back to the RBC Canadian Open, and it bumped former world No. 1 Rory McIlroy to No. 2 while Jordan Spieth dropped to No. 3.
Day's ascent was the only change among the top 10 after the third leg of the FedEx Cup Playoffs. Bubba Watson and Rickie Fowler round out the top five, followed by Henrik Stenson, Jim Furyk, Justin Rose, Dustin Johnson and Sergio Garcia.
On the strength of his runner-up finish outside Chicago, Daniel Berger cracked the OWGR top 50 for the first time. Berger moved from No. 93 to No. 47, and he will be the lone rookie representative at this week's season-ending Tour Championship. Scott Piercy, who finished third at Conway Farms, jumped from No. 69 to No. 43.
Thanks to his one-shot win at the second leg of the Web.com Tour Finals, Chez Reavie both booked his return to the PGA Tour and moved from No. 493 to No. 246. Runner-up Emiliano Grillo moved up 10 spots from 103rd to 93rd, while former U.S. Amateur champ Matthew Fitzpatrick is closing in on the top 100, now 106th after a third-place finish at the European Tour's Open d'Italia.
After announcing back surgery that will keep him sidelined into next year, Tiger Woods dropped nine spots to No. 292 and is expected to fall outside the top 400 by the end of the year.