By Bill Pennington

New York Times News Service

FARMINGDALE, N.Y. — It was supposed to be Rory McIlroy who was going to keep winning major golf championships in bunches. Then it appeared it might be Jordan Spieth, or Dustin Johnson, or Jason Day. Maybe it would be Justin Rose, Tommy Fleetwood or Justin Thomas.

But one of that gaggle was expected to ride the crest of a wave that would anoint golf’s next dominant major champion.

Instead, at least for now, Brooks Koepka has stolen their kingdom.

The vanquished, however, have not given up the fight. Not by a long shot.

Or, as Fleetwood said late Sunday afternoon, “It’s not over yet.”

Despite a few tense late moments, Koepka, who came into Sunday with a seven-shot lead, held on to win the PGA Championship at the formidable Bethpage State Park Black Course. The defending PGA champion, Koepka won for the fourth time in the past eight major championships he has played. Because he also won the U.S. Open in 2017 and 2018, he is the first man to simultaneously hold back-to-back titles in two majors. He will soon assume the top spot in the world golf rankings.

But Koepka’s most prominent challengers, though impressed with Koepka’s performance, were not bowing to his ascension.

Rose, who entered the tournament as the world’s No. 2 player, seemed to look forward to playing Koepka anywhere but the Black Course.

“This golf course was in his wheelhouse; it fit his skill set, and he’s obviously at the top of his game,” Rose said outside the scoring area Sunday afternoon after he finished tied for 29th. “If we had to play this golf course every tournament for the rest of time, I’d be concerned. But we don’t.”

Day, the 2015 PGA winner, conceded that Koepka had dominated the majors the past two seasons but he denied that the rest of the field would be intimidated by his string of victories.

“No, if it was Tiger, probably,” said Day, who tied for 23rd. “Tiger is really the only guy. Brooks is starting to put himself in that category, but really, there’s only a few guys that when they’re at the top of the leaderboard, you can’t catch them.

“But no, not right now. If Brooks keeps doing what he’s doing, then definitely it will have impact on all of us.”

Fleetwood was packing his belongings into a bag next to his locker in the clubhouse behind the 18th green. His message?

“He’s obviously the one who’s winning all the majors; we all see that,” Fleetwood said. “I think it’s good for everybody to have something to aim for. It’s where we all want to be, and it won’t stop the rest of us from trying very, very hard to get there.”

Throughout the field of competitors, there was also a certain amount of bewilderment about some of the specifics of Koepka’s success. One case in point: the speed with which Koepka has accumulated four major victories — his first major title was in June 2017 — seems startling to his colleagues. Especially because in five years on the PGA Tour, Koepka has won just two nonmajor tournaments.

“I just don’t understand why he doesn’t do it more often,” McIlroy said after he shot 69 on Sunday to finish in a tie for eighth. “He obviously gets into these mindsets at the majors, and he really goes and gets into a different sort of state.”

And then there was the question about how long Koepka can extend his impressive streak of top performances in recent major championships (he tied for second behind Tiger Woods at this year’s Masters).

“Ultimately, everything comes to an end; it’s more of managing the plateaus with the lows when you’re at the top,” Day said. “He’ll be in great form and has been and then he’ll hit a little rut. And then he’ll have to work out of it through hard work.”

Paul Casey, who came into the tournament ranked 12th in the world, was asked to compare what Koepka has achieved with Woods’ record in his prime.

“You could say Brooks’ major performance lately is similar,” Casey said. “But then, Tiger was there every week on tour as well, wasn’t he?”