Nearly a year later, the sequence remains something of a blur for Dustin Johnson.
Three strokes ahead of his U.S. Open pursuers to start the final day at Pebble Beach, Johnson opened with a par. He piped his drive at No. 2 long and down the middle. And then …
Before the lanky South Carolinian could fully process the situation, he had a triple bogey.
"With a wedge in my hand," Johnson lamented recently. "It's a funny game."
Though not always fun and games, especially in a major championship. Need corroboration? Ask Nick Watney. Or Rory McIlroy.
"Things went all pear-shaped," McIlroy said of a grim three holes at the Masters. Translation: The bottom fell out.
Hey, no one said trying to protect a lead with 18 holes left in a major would be easy. These days, though, it has become downright treacherous.
Three times in the last four majors, a cushion of at least three shots has given way to a score in the 80s.
Johnson shot an 82 at Pebble Beach. Watney's three-shot lead in the PGA Championship at Whistling Straits was wiped out on his first hole, leading to an 81. Four shots up to begin Masters Sunday, McIlroy still led by one at the turn before sandwiching a triple bogey and a double bogey around a bogey. He shot an 80.
"It's like an out-of-body experience," said ESPN analyst Curtis Strange, a two-time Open champion who remembers his own learning curve.
Sunday major meltdowns aren't exactly new. Arnold Palmer led by seven with nine holes left in the 1966 U.S. Open, only to lose in a playoff to Billy Casper. Greg Norman began Sunday of the 1996 Masters ahead by six; he lost to Nick Faldo by five. Strange squandered a three-shot lead with six to play in the 1985 Masters.
For rapid-fire misery, though, the current run is stunning. Johnson, Watney and McIlroy are among just 12 players since World War II who shot 80 or worse as 54-hole leaders or co-leaders of a major.
Strange was quick to point out a common denominator in the trio: inexperience with final-day major leads.
"There is a huge difference between taking a 54-hole lead into (the last day of) a U.S. Open versus a regular tour event," he said. "It's hard to put into words the ramped-up nerves from anxiousness, sleeplessness, pressure."
Said ESPN colleague Andy North, another two-time Open champion: "You have to just relish the fact that your stomach is upside down and you didn't sleep very well."
Gio Valiante, a mental-game coach who works with Justin Rose, Camilo Villegas and Stuart Appleby, said players have to find a way to control the added energy that comes with a major Sunday.
"It pushes a golfer to either become quick or tight — or both," Valiante said. "Then out on the course, it amplifies any emotion they have. The highs feel higher, the lows feel lower. You go on an emotional roller coaster."
After Johnson's and Watney's rounds were marred by early triple bogeys, Valiante noted: "It looks like they're lost. They don't have a default. … It shows you how everything's amplified."
In retrospect, both have acknowledged moving seemingly in fast-forward as things began to unravel.
"I was going very, very fast — swinging fast, walking fast, thinking way ahead," Watney said. "What I learned is that I'm never going to be able to block out those feelings. I just have to learn how to handle them. I don't have it, but I'm getting there."
To their credit, both Watney and Johnson own significant post-meltdown victories. Johnson captured the BMW Championship during last year's FedEx Cup playoffs; Watney claimed the title at the World Golf Championships event at Doral in March. Though not majors, the learning showed.
"To know what to expect in that situation is definitely a bonus," Johnson said.
Now all that's left is to try to grab the 54-hole lead this week at Congressional — and turn those ill-fated lessons into positive results.
"Sometimes you have to experience that before you learn how to do it," Jack Nicklaus said of Sunday pressure. "But if you don't learn from it, then you're not paying attention."