At one time on the back nine, after McIlroy eagled the par-5, 14th hole, there were six players tied for the lead at 6 under, three shots worse than where Spieth, Schauffele and Kisner began the round after leading at the 54-hole mark.
Tiger Woods was on the range, preparing to tee off on the weekend at the British Open for the first time since 2014 at Hoylake.
"I'm going to have to have an fantastic round to get myself in it", he said.
The pair of course had some history - Molinari beat Woods with the famous concession on the final hole of the 2012 Ryder Cup at Medinah, the completion of Europe's famous comeback victory over the USA. At one point, he went over to the practice green, but not to prepare for a playoff. "Then ask me again".
Molinari assumed the lead at 7 under on the 14th hole with a two-putt birdie, and Schauffele tied him with a like birdie two groups hence. Jordan Spieth was tied for the lead. "I won't lie. I had too much to drink last night", he said after shooting 67 and finishing in a three-way tie for sixth.
The "where I was" referred to the years of debilitating back pain finally solved by a spinal fusion 15 months ago that allowed him to resume his career after four years of severely-curtailed appearances.
One of those runners-up finishes came after blowing a five-shot lead with nine holes to play in defence of his Masters title, while the fourth place came when he finished a shot outside a three-man play-off for the 2015 Open at St Andrews in pursuit of the third leg of an unprecedented calendar grand slam. But as it happens, I shot 67. Woods and Spieth were among five contenders to make double bogeys.
"I've got a bit of experience at this, maybe more so than some of the other guys on the leaderboard", said McIlroy.
Peter Morrison British Open champion Francesco Molinari of Italy is congratulated by Tiger Woods at the end of the fourth round
"Even if I don't play my best golf and don't shoot the scores I want, I'm going to go down swinging, and I'm going to go down giving it my best", he said.
Francesco Molinari had a 66 and will play in the third-to-last group with Woods.
By contrast, Molinari gained his first shot of the day at the par-five 14th and, just as crucially, holed clutch par putts on the 15th and 16th.
Another American Kevin Chappell is two shots off the lead with Italy's Francesco Molinari on six under and Woods another stroke back alongside Rory McIlroy, Tommy Fleetwood, Webb Simpson, Alex Noren, Matt Kuchar and Zach Johnson. "I've watched this through the PGA Tour this year day in and day out, seeing him work as hard as anyone else". They all dropped shots on a day when there was no time to be going backward. He missed a short birdie putt and tapped in for par to finish off his final-round 71.
"I really felt like I had control of the golf ball and, on top of that, I made some longer putts, which was nice".
Just nine shots separated the 79 players who made the halfway cut at Carnoustie, where Paul Lawrie famously came from 10 strokes back with just 18 holes to play to win the Claret Jug in 1999.
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It was one of the few times Woods was out of position all afternoon in a round where he hit driver six times, compared with three times in the second round and once on Thursday.
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