Those same 18 holes separate McIlroy from a fourth major victory before his 26th birthday; Fowler, Day and Stenson from their first major win; Mickelson from his sixth career major and incredibly, his first top-10 finish in the States this year; Oosthuizen from his second career major; and if you believe in healthy-sized comebacks, Scott and Furyk from their second career majors and Westwood from his first.
McIlroy shot a 4-under-par 67, but there was nothing stress-free about it. He grinded and, on occasion, showed a moment or two of frustration and anger. The club slam after he fluffed a downhill chip shot on No. 12 comes to mind.
But McIlroy recovered. His mantra during this incredible golf run has been patience, and he showed it during a round in which a 67 could have swelled to a 69 or worse if not for a pair of world-class bogey saves.
How can you not love a Sunday when McIlroy, once again a 54-hole leader at a major, can join the conversation as a legitimate pursuer of Jack Nicklaus' record 18 major victories?
"Loving it," said McIlroy. "I'm loving it. It's where I want to be. It's the best place to be in a golf tournament. I couldn't want to be anywhere else."
How can you not marvel at the possibility of the obscure Wiesberger, who comes from a country where you could fit all the golf fans into Tennessee's Neyland Stadium, winning this thing?
How can you not drool at the prospect of another Mickelson family reunion and hugfest at the 18th green?
"It's so fun for me to be back in the thick of it ... being in contention heading into Sunday and not having to get up at 6 o'clock in the morning to tee off," said Mickelson, who has been in way too many dawn-patrol pairings this year.
And how can you not root for the likable and respected Fowler, all of 25 and paired with the 44-year-old Phil, to break through?
"We'll have a good time, that's for sure," said Fowler.
Imagine that, fun at a major. That's the PGA Championship. That's Sunday.