(CNN) Bulletproof, immovable, and playing a different game to the rest, Brooks Koepka is doing a better impression of Tiger Woods than Tiger Woods.
The 29-year-old shot a course-record 63 on day one and added a 65 Friday to stretch his lead to seven shots at 12 under to stamp his authority on the 101st US PGA Championship at Bethpage.
Despite the Black course's fearsome reputation, Koepka's 36-hole score of 128 is a major championship record, his halfway lead is the largest in PGA Championship history, and he bettered the Masters champion by 17 shots as Woods missed the cut.
Even then, Keopka insists he was "battling" his swing a bit.
"Today's a new day, doesn't matter what you did yesterday," the defending champion, who has won three of his last seven majors, told Sky Sports.
"I'm very pleased. It's a tough golf course, you've really got to battle and I'm proud of the way I hung in there.
"It's something I've battled my entire life so it should be an easy fix."
READ: Woods struggles as Koepka coasts clear at US PGA
In pictures: The 2019 PGA Championship so far
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.
Rearview mirror
While Woods' 15th major title had many misty-eyed for his domineering heyday, Koepka is showing why he is now the most imperious player in major golf with an explosive marriage of power, finesse and ice-cool emotions. Koepka, who was tied second at Augusta, credits his ability to stay on an even keel as one of his best attributes.
"It's massive," he added. "I don't think people realize how difficult it is and how you have to let things roll off your back, laugh about it and move on. It tests your patience, for sure."
The Floridian was bogey-free through 27 holes on Long Island, and despite two bogeys coming home Friday he kicked on to leave the field trailing in his muscular wake.
A distant sight in Koepka's rearview mirror was a rejuvenated Jordan Spieth at the front of the chasing pack with a four-under 66 to show signs of a rosier future after enduring a slump of late. Spieth needs just the US PGA to become only the sixth player to clinch the career Grand Slam of all four major titles and a first win since the 2017 Open.
Alongside Spieth on five under was 2013 Masters champion Adam Scott, whose blistering surge to six under for the day after 14 holes put him in with a shout of beating the major record of 62 before he faltered towards the end to card 64.
And what of Woods himself? Overshadowed in performance -- if not fan adoration and volume level -- by playing partner Koepka, he looked out-of-sorts compared with that magical Masters triumph on his last outing.
The 43-year-old, who only played nine holes in practice, hit only three fairways off the tee Friday, and was unable to build any kind of momentum despite constant urgings from the boisterous New York crowd.
Needing a birdie up the last to make the cut at four over, his approach was wayward and he was unable to chip in from the fringe, adding a 73 to his opening 72 to finish five over to miss the cut by one.
READ: Woods' Masters win has Nicklaus "shaking in my boots"
READ: 'It's surreal,' says Woods of 15th major
Tiger Woods: From highs to lows
Tiger Woods clinched his fifth Masters and 15th major title with victory at Augusta in April.
The former world No. 1 had not won the Masters since 2005, and it was his first major win since 2008.
A month after winning the Masters, Woods received the nation's highest civilian honor, the Presidential Medal of Freedom, from President Donald Trump.
Woods won the season-ending Tour Championship in September 2018. It was his first title in five years following a succession of back injuries.
Signs that Woods was back to his best were obvious at August's PGA Championship, where he finished runner-up to Brooks Koepka. It followed an impressive showing at July's British Open, where he briefly topped the leaderboard.
Woods made an impressive return to competitive golf in 2018 after multiple back surgeries in recent years. He played his first Masters in three years in April 2018.
The four-time champion had back fusion surgery -- his fourth procedure -- in April 2017 and returned to the game pain-free in December. He finished tied 32nd at Augusta.
Woods was touted as one of the favorites after impressing in his early-season events. He also set tongues wagging by playing a practice round with old rival Phil Mickelson, right.
Woods finished tied second at the Valspar Championship in March 2018 and followed it up with a tie for fifth at the Arnold Palmer Invitational at Bay Hill. The hype needle moved into overdrive.
Woods set out on his legendary path by becoming the youngest winner of the Masters -- at 21 -- with a record 12-shot win in 1997.
One of his most remarkable feats was winning his first US Open by an unprecedented 15 shots at Pebble Beach, California, in 2000, sparking a streak never seen before or since.
Woods' victory in the 2001 Masters meant he held all four of golf's major titles at the same time, dubbed the "Tiger Slam."
Woods' win rate, his dedication to fitness training and his desire to succeed were changing golf. Prize money rocketed because of Woods. Off the course, he married girlfriend Elin Nordegren in 2004.
Woods showed rare emotion when he broke down in tears on the shoulder of caddie Steve Williams following his win in the 2006 British Open at Hoylake, months after his father and mentor Earl passed away.
Despite being visibly hampered and in pain from a knee injury, Woods won the US Open in breathtaking fashion at Torrey Pines, California, in 2008. It was his 14th major title to leave him only four behind the record of Jack Nicklaus. He was later diagnosed with knee ligament damage and two fractures of his left tibia. He missed the rest of the season after surgery. It is still his last major title.
In December 2009, Woods crashed his car into a fire hydrant outside his home. As the big picture emerged it was discovered Woods had been conducting a series of extra martial affairs. He took three months away from the game to sort out his private life.
In February 2010 Woods addressed the world's media to explain and apologise for his actions. His infidelity led to divorce and was the beginning of a downhill slide in Woods' playing career. By October he lost the world No. 1 ranking, a position he had held for 281 consecutive weeks
Back in the fold, Woods earned his first win in two years at the
Chevron World Challenge in December 2011, a charity tournament he hosts that does not count on the PGA Tour money list.
Woods was back in the winner's circle in 2013, lifting five titles, including the Arnold Palmer Invitational, to get back to the top of the rankings.
In March 2013, Woods and Lindsey Vonn announced
they were dating on Facebook. In January that year, the champion skier had finalized her divorce from Thomas Vonn, after initializing proceedings in 2011. In May 2015, Woods and Vonn announced their breakup, with the golfer claiming he "hadn't slept" in the days following.
Later in 2013 there were signs all was not well as Woods was seen to be in pain as he picked the ball out of the hole at the Barclays tournament in August. He missed the Masters the following April for the first time since 1994 to undergo back surgery.
Woods pulled out of the Farmers Insurance Open in February 2015, and struggled with injury and form for the rest of the season.
Woods cut a dejected figure at that year's US Open as he struggled with his game and carded rounds of 80 and 76 to miss the cut.
In August 2015 Woods made his last appearance for 15 months to undergo follow-up back surgeries. At one stage during his rehabilitation, Woods spoke of there being "no light at the end of the tunnel" -- and with one eye on his fading career, he suggested "everything beyond this will be gravy."
Woods made a much-anticipated return to golf in December 2016, showing signs of promise with the highest number of birdies in the field -- 24 -- but he also made a number of costly errors to finish third from last in the 18-man event.
He missed the cut in his first event of 2017 in the US and pulled out after the first round of the Dubai Desert Classic in February, citing back spasms. He underwent a fourth back prodecure in April.
The golf legend
was arrested Monday, May 29, on suspicion of driving under the influence. He was booked into a local jail in Florida and released a few hours later. He said in a statement he had "an unexpected reaction to prescribed medications."
In August Woods entered a first-offender program and pleaded guilty to reckless driving on October 28. He will avoid jail unless he commits major violations of his probation.
Woods returned to golf after 301 days at the Hero World Challenge in the Bahamas on November 30 2017. He carded a three-under first-round 69 and appeared pain-free and hungry to resume his career.
' I need to start feeling better'
The world No.6 could have gone back to the top of the rankings for the first time since May 2014 had he won and other permutations worked in his favor, but he said illness and fatigue after the high of the Masters were contributory factors.
"It's just the way it goes," Woods told reporters. "You know, just don't feel well and just not able to do it. Resting would be better, so I would have energy to play. You know, unfortunately I just didn't -- made too many mistakes and just didn't do the little things I need to do.
"I've enjoyed being the Masters champion again, and the PGA was a quick turnaround, and unfortunately I just didn't play well."
Woods admitted that after his catalogue of back injuries, culminating in spinal fusion surgery in 2017, there will be "days and weeks when it's not going to work."
"There's no reason why I can't get up to speed again and crank it back up," he said.
"I've got to start feeling a little bit better first before that happens.
"I just wasn't moving the way I needed to. That's the way it goes."
Should he go on to win, Koepka's superiority would be somewhat reminiscent of Woods' stretch from 2000-2002 when he won six of nine majors, starting with the US Open by a record 15 shots having led by six at halfway at Pebble Beach -- incidentally the venue for this year' US Open in June.
Or from 2005-2008 when he won six of 14 and was no worse than fourth six other times.
"What Brooksy did, he's driving it 330 yards in the middle of the fairway," added Woods. "He's got 9-irons when most of us are hitting 5-irons, 4-irons, and he's putting well. That adds up to a pretty substantial lead, and if he keeps doing what he's doing, there's no reason why he can't build on this lead."
Koepka has been vocal in the past about not receiving enough recognition, but he admits he uses any perceived slights as fuel.
Rocket fuel, it would seem, as he becomes increasingly box-office viewing.
"I'm just going to keep doing what I'm doing, put the pedal down and try to build a bigger lead," said Koepka.