AUGUSTA — His daymare almost over, the light fading on the rubble of his first great collapse, Jordan Spieth had one more chore to perform before he could escape the scene.

You see, last year’s champion must help Sunday’s winner into his new green jacket, signifying the transition of power at the Masters.

A whispered “You’re welcome,” from him would have been appropriate during the ceremony this time, although it never happened. Spieth’s far too cool for that.

For Danny Willet’s Masters victory was part his own determined performance and part the gift of the day that Jordan Spieth learned he was vulnerable.

First, it was inside the Butler Cabin, for the CBS cameras, where Spieth sat as silent as a man in shock while the Brit Willett was asked about his wonderful life. Soundlessly then, Spieth, so fresh off the ruinous quadruple bogey on Augusta National’s shortest hole that the memory hadn’t had time to clot, slipped the jacket about Willet’s slender shoulders.

Then again outside, after an interminable 15 minutes while Billy Payne thanked all in attendance — almost individually — having to sit awkwardly next to the beneficiary of his worst moment on a golf course. A quick handshake. Another fitting, this time Spieth carefully turning down the collar for the Masters champion before stepping out of the picture and applauding his own defeat.

Oh, Jordan, could we recreate it one more time for the cameras? Here, do it again and then move aside, please.

“As you can imagine,” he said afterward, “I can’t think of anybody else who may have had a tougher ceremony to experience.”

After giving his regards to Willet, Spieth then returned to the subject of his role in the ceremony: “I felt that I stood up there and smiled like I should, and appreciated everybody who makes this great tournament possible.”

I don’t know what was harder to watch, the quadruple bogey 7 Spieth took on the 12th hole or this ceremony that bordered on an exercise in self-flagellation.

On second thought, yes, I do. His No. 12 was an Alfred Hitchcock-directed train wreck.

Who knew Spieth was capable of such calamity, of such poor judgment, of such a careless swing under duress? Spieth certainly didn’t. He does now.

Having made the turn Sunday with a five-stroke lead over Willett, Spieth was almost certain to become just the fourth back-to-back Masters champion ever. He was fresh off a run of four straight birdies, and looked to be matching his runaway of a year ago.

“It was a dream-come-true front nine,” Spieth said. “And I knew par was good enough (on the back to win) and maybe that is what hurt me.”

Those back-to-back bogeys he made on Nos. 10 and 11 were survivable, such was the cushion he has built.

Then he drew back his 9-iron on little No. 12, such a picturesque nook that forever now will be the setting of painful flashbacks.

“Right club, just the wrong shot,” Spieth said. He had hit a cut shot there in 2014, and splashed a ball in Rae’s Creek, destroying any outside chance of winning that year.

He’d try to do it again in 2016. “Ultimately I should have just played a draw on that hole,” he said. This time the ball hit right and short, catching the bank and rolling back into the water.

And the reload never had a chance. Taking a divot that seemed the size of a bear skin rug, Spieth’s chunky second swing resulted in another ball sacrificed to creek. In a matter of minutes, he went from three up and alone in first to a tie for fourth.

And what he give, Willett wasn’t about to give back. What should not be obscured by Spieth’s collapse is the fact that the 28-year-old from Rotherham, England, was perfect this day. No bogeys. Three-under on the back nine on Sunday, when they say these things are supposed to be decided.

Meanwhile Spieth will look back on his own inability to get through the back nine in one piece — for the tournament he was 8 under on the front, 6 over on the back.

“Listen, I had my B-minus game tee to green and I made up for it around the greens with my putter,” Spieth said. “Ultimately, you just have to have your “A” game — every single part — and I just didn’t have those iron swings, as it showed on the back nine.”

A year ago, he took Augusta National apart like it was made of Lincoln Logs.

And now, it returned the favor, peeling away the layers of seeming invincibility until all that was left was another Sunday victim of springtime in Augusta.

He went from the unstoppable Masters force to Greg Norman in two swings of a club.

The man who stood there in the Sunday twilight as the polite former champion was roiling on the inside.

“Boy, you wonder about not only the tee shot on 12, but why can’t you just control the second shot?” Spieth said.

“Big picture, this one will hurt. It will take a while.”