Days after claiming that "sometimes the majors are the easiest ones to win," he certainly didn't make it look that way during the final round.
Koepka's fourth major win looked all but guaranteed at the start of the day, as the 29-year-old entered with a seven-shot lead and had barely flinched all week. However, the wind picked up heavily on the back nine and created unexpected drama at Bethpage Black.
After birdieing the par-4 10th to get to 13-under, Koepka held a six-shot edge over Johnson with eight holes to play. But then, three wayward drives and a sloppy display on the short par-3 14th led to four consecutive bogeys for the leader. As Koepka was unraveling, Johnson rolled in a birdie putt to climb within one.
And that's as close as it got.
Johnson carded two poorly-timed bogeys on Nos. 16 and 17 to quickly hand Koepka a three-shot edge.
Brooks dropped another shot on No. 17 but scraped together a par on his final hole to shoot a 4-over 74, good enough to hoist the Wanamaker Trophy for a second straight year.
''I'm just glad I don't have to play any more holes,'' Koepka said, according to the Associated Press' Doug Ferguson. ''That was a stressful round of golf. I'm glad to have this thing back in my hands.''
Koepka joins Tiger Woods, Jack Nicklaus, and Ben Hogan as the only players to win four major championships in a span of eight starts since 1934. He becomes the first player in history to win back-to-back PGA Championships and U.S. Opens and the first to hold two different majors in back-to-back fashion at the same time.
His wire-to-wire win at Bethpage vaults him into the No. 1 spot in the Official World Golf Rankings and pads his bank account with a $1.98-million payday.
Here's how the top of the leaderboard finished:
|Place||Player||Total to par||Round 4 score|
|T8||Erik Van Rooyen||+1||73|
Johnson is still searching for his elusive second major win. He finished alone in second by four shots and has now finished as the runner-up in all four major championships he's played in his career.
With a tied-for-third showing, Jordan Spieth turned in his best finish since the 2018 Open Championship. He showed signs of his former major-winning self and led the field in strokes gained: putting.
The next major championship will be the U.S. Open at Pebble Beach Golf Links in California beginning June 13.