Known more for his power with the driver than touch with the putter, Johnson came up with two brilliant shots on the par-five 18th hole to set himself up for an US Open title.
A three putt from 12 feet, however, allowed Jordan Spieth to walk off with the trophy.
“Whatever the putt did on the last hole, I don't know,” a stunned Johnson told reporters.
“It's tough. I've got a chance to win the US Open on the last hole. I was trying, just didn't work out.”
Johnson has experience major disappointment before but Sunday's finish may sting more than any other, coming on a Chambers Bay layout perfectly tailored to his power game.
At the 2010 US Open at Pebble Beach, Johnson squandered a three-shot lead in the final round with an 82.
That same year at the PGA Championship at Whistling Straits, he was hit with a two-stroke penalty for grounding his club in a bunker on the 18th hole and missed out on a playoff for the trophy with Kaymer and Bubba Watson.
After a scrappy final round that included three bogeys over four holes to kickoff his back nine, Johnson stepped onto the 18th green with major glory just a 12-foot eagle putt away.
With the his fiancee Paulina Gretzky and their newborn son looking on, Johnson calmly measured the putt, stepped up and watched the ball roll past the cup.
He then missed a four-foot birdie putt coming back to squander the chance of forcing an 18-hole playoff on Monday.
“Disappointed. I played really well. I didn't make any putts today, I really didn't,” Johnson told reporters. “I had all the chances in the world.
“I did everything that I could. I tried my damndest to get in the hole I just couldn't do it.”
While Johnson received plenty of support and comfort from family and fans, it was his partner's father Wayne 'Great One' Gretzky, he said, he would turn to for some perspective.
The former-NHL great had plenty of experience of dealing with disappointment over a record smashing career in ice hockey.
“I'll see him in a few minutes as soon as I leave here,” said Johnson.
“I'm sure we'll talk about it. At the end of the day, golf is golf. I've got my family and that's most important to me.
“My trophy at the end of the day is holding up my little man. I couldn't be more proud of myself and my family.
“No matter what I'm going to keep my head high and I'm going to be happy.” – Reuters
Original source: More major heartbreak for Johnson