"He was focused. He had his mind set on what he wanted to do," Austin told a small group of reporters before 2019 champion Tiger Woods helped Dustin into his green jacket in a low-key ceremony.

"It was nerve racking for me."

Johnson fulfilled a childhood ambition with his Masters triumph and did so in style – posting an Augusta National record total of 20-under-par 268.

"This is one we always dreamed about, growing up down the road," Austin Johnson, who spent his childhood with his brother in Columbia, South Carolina, about an hour's drive from Augusta.

"I remember being out on a putting green with Dustin late at night and every putt was to win the Masters.

"I couldn't be more excited for him.

"I see how hard he works and how close he's come to winning some majors.

"Having four 54-hole leads and not converting any of them, this is a big weight off him."

"I remember being out on a putting green with Dustin late at night and every putt was to win the Masters. I couldn't be more excited for him." – Austin Johnson

Dustin Johnson has had other bitter disappointments in major championships but rather than vent his frustrations he has tried to cope by learning from them.

Asked how the World No.1 behaved on the eve of Sunday's final round while holding another 54-hold lead, Austin said: "He's always pretty much the same DJ.

"Laid back, pretty calm.

"You can't tell if we're coming down the stretch of a major or if we are laying on the couch watching football."

But don't think the competitive fire doesn't burn in him.

"He doesn't throw clubs or curse at me but that's because he's a class act," Austin Johnson said.

"It doesn't mean he doesn't care. He's a Southern guy, laid back. We talk a little slow and people think we don't care.

"Those losses definitely hurt.

"But I think we learned from them.

"I think we've matured and grown as a team and learned from our mistakes, from not converting the leads."