In Matsuyama's return to the Waste Management Phoenix Open, he again entered a playoff on Sunday to defend his title, this time against Webb Simpson. On the fourth playoff hole, Matsuyama made birdie to win the tournament for the second time in as many years. After finishing second in the 2017 U.S. Open at Erin Hills, while the top three players in the world at the time (Dustin Johnson, Rory McIlroy and Jason Day) failed to make the cut, Matsuyama reached 2nd in the Official World Golf Ranking, his highest ever, and the highest ever for a male Japanese golfer.