TULSA, Okla. — Stewart Cink hovered over his short par putt on the 18th hole in Thursday’s opening round of the PGA Championship at Southern Hills and had a flashback. 

“The pin today was pretty much in the same location as it was on that Sunday of the U.S Open in 2001 — even though the green is different,’’ Cink told The Post. “That crossed my mind when I had to tap in for par.’’ 

That was the worst train wreck the 48-year-old Cink has ever been a part of on a golf course. 

That was in reference to the 18-inch bogey putt Cink mindlessly missed on the 72nd hole of that ’01 U.S. Open that, had he made, would have landed him in the 18-hole playoff eventual winner Retief Goosen and Mark Brooks competed in the following day. 

That is something that would become a prime storyline come Sunday if Cink can do more of what he did on Thursday — which is shoot a 1-under 69 in the first round — and win this PGA on the very grounds where he lost a chance to win that 2001 U.S. Open. 

It’s early, of course. Only one round has been played and the time from Round 1 to Round 4 in major championships is measured in dog years. But Cink enters Friday’s second round a mere four shots out of the lead held by Rory McIlroy. 

Dreamers can dream. Sometimes the coolest stories do unfold the way you want them to by week’s end. 

Here’s how Cink’s story in 2001 went sideways: 

He and Goosen were tied for the lead on the 72nd hole. Goosen’s approach shot was safely on the green, some 12 feet from the cup. Cink’s approach shot airmailed the green, forcing him to chip onto it and leave himself a 15-footer for par. 

Cink, considering his par putt a must-make because Goosen wasn’t going to three-jack an uphill 12-footer, ran his attempt 18 inches past the hole and was gutted. Trying to get out of Goosen’s way, Cink went to brush his 18-incher in for bogey and missed it, taking double. 

At the time, his emotion was simply “being embarrassed by missing such a short putt,’’ having little idea how consequential the miss would be moments later when Goosen three-putted for bogey. 

“It’s the saddest thing I’ve ever seen in watching sports,” fellow player Paul Azinger said at the time. 

“When I missed my par putt, I felt like it was over and I could not find any focus on the next putt,’’ Cink was saying Thursday, recounting the madness. “I didn’t rush it or anything, I just never got there mentally. Once that par putt went by as far as I was concerned that was my chance. It was done and I didn’t have anything to focus on anymore. 

“It just looked like Retief was just going to mindlessly two-putt to win and … ’’ 

Cink recalled his mind-rush in that moment: “Oh my gosh, I cannot believe that that putt that I just missed and didn’t even think mattered is going to end up costing me.’’ 

Cink, a spiritual man, quickly made peace with the disappointment of that moment, saying, “I don’t think it was meant for me to win that one.’’ 

It was the external reaction in aftermath that nearly suffocated him. 

He qualified for his first Ryder Cup team in August 2001 and the Sept. 11 attacks postponed it for a year. It turned out to be an agonizing year of taunting for Cink “because I was going to make my Ryder Cup debut and I was known as the guy that missed that short putt at Southern Hills at the U.S. Open.’’ 

He recalled one writer previewing the 2002 Ryder Cup and writing, “Something that Cink will never hear at the Ryder Cup: ‘That’s good.’ ’’ 

“I read that and it was pretty hurtful,’’ he said. “That was the period of time I struggled with.’’ 

Cink persevered, winning six times since that blown chance at Southern Hills, including his career-crowning moment, the 2009 British Open at Turnberry, where he outlasted 59-year-old Tom Watson in a playoff. That more than made up for the devastation of 2001 at Southern Hills. 

Can you imagine if Cink is able to win this week, particularly with his 25-year-old son, Reagan, caddying for him? Reagan was a 4-year-old for Cink’s dubious 2001 moment and has no memory of it. 

It’s a tenet of the golfer’s credo not to think ahead, but, man, what if? 

“It would be awesome to, I guess, kind of vindicate myself here,’’ Cink said. “This is a golf course that is right up the alley of a player like me — I’m experienced, I’ve been around the block, I’ve got my scars.’’ 

Cink’s most prominent scar of all has been long healed, but man, what if on Sunday on the 72nd hole at Southern Hills … ?