He laid up, pitched to three feet, and made a par.
In the end, he shot 71 to post five under and finish three shots behind playing partner Francesco Molinari, who posted a bogey-free 69 to take the clubhouse lead at eight under.
"I got beaten up around here a few times already in the past". Today was a day that I had a great opportunity. It's a really tough course. I was calm - you know, as calm as you can be playing in the last round of a major close to the lead, playing with Tiger.
A month ago, he was anxious about keeping his PGA TOUR card and qualifying for the FedExCup Playoffs. Molinari is now seventh in the FedExCup, a leap of 116 spots in the past four weeks.
Now at a career-best No. 6 in the world, he has won three times and been runner-up twice in his last six tournaments.
The 24-year-old American put a title-less year behind him over the first three days at Carnoustie and after a magnificent six-under-par 65 on Saturday, looked primed to repeat his victory at Royal Birkdale 12 months ago.
Molinari arrived with the confidence to conquer Carnoustie. "It didn't feel any different to be next to the lead and knowing what I needed to do".
Now Molinari owns the lowest score (276) in an Open Championship at Carnoustie.
As it turned out, that birdie would have just briefly brought him to within 1 stroke - as Molinari made his putt for birdie to seal the tournament.
"To look at the names on that Claret Jug, what can you say?"
Over the daunting closing stretch, Woods watched helplessly as Molinari, as reliable as the tide coming in off the North Sea, plodded his way to victory. Like 11, he chose to go aggressive, attempting a high-risk flop shot over a bunker instead of playing safely past the pin and taking double bogey out of play.
I said off camera that I thought he was going to struggle being in the lead of a major championship.
Tiger Woods is in contention for the claret jug again. Hitting into the gorse didn't have the same effect this year.
Spieth bogeyed No. 5 then made double-bogey at the sixth hole after taking a drop then three-putting.
His charge was a 2-under 69 in the strongest wind of the week, the only player from the last four groups to break par.
Spieth, who started the day in a three-way share of the lead with Kisner and Shauffele, crashed with a 76 to wind up equal ninth a further stroke back with United States countrymen Tony Finau (71) and last year's runner-up Matt Kuchar (72). Never got down on myself. "It didn't feel any different to be next to the lead and knowing what I need to do".
"I flinched, but I've had things like that happen a lot in my career with people who tried to time it". Waiting for him afterward were his two kids, Sam, 11, and Charlie, 9, both of whom were either too young or not yet born when Tiger last won a major in 2008, when he was at the peak of his powers. My stroke is there.
"Throughout the round, (I) felt the most comfortable that I've felt at a Sunday in a major in my life", Spieth said. "So I could use it to my advantage, and, just did a great job at that".