Sunday's play will decide the victor of the fourth and final major of the golfing season with the PGA Championship itself moving to a May date for the 2019 season.
Shortly after 5 p.m., he had a 20-foot putt on the 16th green that would've tied him with Koepka, who was two holes behind but may as well have been playing on another course compared to the frenzy in front of him.
And then there was the multitude that roared in utter delight when Tiger Woods made a run up the leaderboard, all but urging the 14-time major champion into contention as he battled his swing through the front nine and his stamina down the stretch.
Koepka is the first man to win two majors in the same calendar year since Jordan Spieth won the Masters and U.S. Open in 2015.
Plenty have been quick to write Woods off, but this performance - coupled with his impressive showing at the British Open in Carnoustie last month - suggests he is still a force to be reckoned with.
"But it was good to be back feeling like I had a chance to win a major".
A brilliant reception for Tiger as he heads back to the clubhouse.
It left a sense of anti-climax, but Woods is still within reach of his 15th major, a situation few would have predicted at the start of a year which has seen the 42-year-old resurrect his career after debilitating injuries.
The final round of the final major of the year is buzzing with possibilities. "I didn't know when I was going to start this year and how many tournaments I was going to play, how well I was going to play". "I'm just so thankful to be here".
Koepka was well aware of Woods' charge.
"I don't think someone's going to run away with it tomorrow; it's still a major championship".
"I'm just very pleased at what I've done so far ... going from where I've come from, to now over the past year, it's been pretty cool".
The 2017 and 2018 U.S. Open Champion added the 2018 PGA Championship to his trophy case with a 66 on Sunday to post 16-under, beating Woods by two and Scott by three.
However, Koepka was immune to the pressure and calmly went about his business. "This is the first real "Tiger effect" I guess you could say". You know kind of the ground swell.
"I mean, you have to because you know he's right there if you fall."
Utahn Tony Finau made six more birdies Sunday, completing the tournament with a 2-under-par 68 that gave him a tie for 42nd place.
"I've got to shoot a low round", Woods said.
Tiger just has to wait and see if he makes the squad.
Through it all, Koepka was calm, making shot after shot when it was needed the most.
A month removed from his sixth-place finish in the British Open at Carnoustie, where he led with eight holes to play, Woods on Sunday posted the low round of the day with a 6-under-par 64 and finished runner-up to victor Brooks Koepka.
Three-time major victor Jordan Spieth finished in a tie for 12th at 8 under after a 66 on Sunday.
There is little doubt that Koepka is now a major force on the circuit, and a potential world number one in the making. Scott missed a 6-foot birdie putt on the par-5 17th that would have pulled him to within one shot - right after Koepka missed from the same range - and then made bogey on the 18th for a 67 to finish alone in third. I said to my caddie a couple of holes before it was the most fun I'd ever had and then that happened. "He's someone that I'm glad he's on my team, and I don't have to play against him".