
Brooks Koepka successfully defended his PGA Championship title after a thrilling finish at Bethpage Black.

The 29-year-old clinched his fourth major in eight events after overcoming a late wobble at Bethpage.

Koepka led by seven ahead of the final day but four straight bogeys on the back nine let in his close friend and the then world No.1 Dustin Johnson, who narrowed the gap to one.

England's Matt Wallace was in the chasing pack well behind the leading two at Bethpage.

Popular veteran Phil Mickelson is a fan favorite in New York.

Koepka said the back nine was "very stressful" as he battled his own mistakes and the pressure exerted by Johnson.

Japan's Hideki Matsuyama of Japan chips onto the 13th green during the final round of the PGA Championship.

Tyrrell Hatton of England makes a shot out of the rough amidst the gallery on the ninth hole during the final round.

Three-time champion Jordan Spieth finished tied third to reignite his major form after a slump of late.

Johnson faltered coming home and has now finished runner-up in all four of golf's major tournaments.

Brooks Koepka drives off the 12th tee during the third round.

Jordan Spieth hits out of a bunker onto the fifth green during the third round of the PGA Championship golf tournament on Saturday, May 18.

A spectator rests in the shade of a tree along the seventh fairway during the third round.

Phil Mickelson walks up to the 18th green during the third round.

Dustin Johnson greets spectators as he walks to the 12th tee.

Brooks Koepka picks his ball out of the hole after putting on the eighth green.

Brooks Koepka plays his shot from the 17th tee during the second round of the 2019 PGA Championship on Friday, May 17, in Farmingdale, New York. Koepka, in the lead after the second round, set a record for the lowest 36-hole score in major championship history.

Tiger Woods tees off on the 18th hole. Woods failed to make the cut for the final two rounds after shooting a three-over 73, ending the tournament at five over.

Fans cheer for Tiger Woods on the 13th hole.

Jordan Spieth of the United States lines up a putt on the 16th green during the second round of the US PGA Championship. At the end of the round, Spieth was tied second with Australian Adam Scott.

Fans line up near the the eighth green during the second round.

World No.1 Dustin Johnson reacts after putting on the seventh green.

Phil Mickelson plays a shot from the rough on the third hole.

Brooks Koepka, left, shakes hands with Tiger Woods after finishing the second round.

Tommy Fleetwood plays a shot from the fourth tee.

Brooks Koepka with yet another impeccable drive on the 15th tee in a thrilling opening round of 63 -- a course record.

April's Masters victory felt a long time ago for Tiger Woods; the 15-time major winner regularly located both rough and bunker in a first round that lacked the control of last month.

Alex Noren takes stock on the third hole of this thrillingly difficult golf course. If you miss the fairway and the bunkers, the long grass will eat you alive.

John Daly, the PGA Championship winner in 1991, was making a bit of history at Bethpage Black. He has been given permission to use a golf cart at the tournament as a result of his osteoarthritis in his right knee.

Phil Mickelson and Jason Day salute their fans as they complete solid first rounds of 1 under par.

Flowing locks blowing in the wind, Tommy Fleetwood in action en route to a very respectable first-round effort of 3 under par.

Brooks Koepka putts on a hulking eighth green, watched by fans who were witnessing a clinic from the three-time major winner.

Jason Day's only major victory came in the 2015 PGA Championship. Here he is, one of many to find one of Bethpage Black's daunting sandpits.

Dustin Johnson, the world No.1 and a favorite among many experts, tees off at the 17th.

As Phil Mickelson watches his tee shot fly into the distance, his fans make sure to leave with their own memories.

An image to highlight the extent of this monster golf course. Narrow fairways, damp, long roughs, gaping bunkers, overhanging trees. But then, Brooks Koepka on the tee, helping himself to the most supreme first round of major golf imaginable.