World No.1 Dustin Johnson has shed his unwanted tag of one-major wonder, denying gallant Australian runner-up Cameron Smith, to win the Masters in record fashion.

Johnson withstood a fierce early challenge from Smith to close with a four-under-par 68 to finish as a five-stroke winner over Smith and South Korean Sungjae Im, who both closed with steely 69s.

The American’s total was the equal-lowest under-par score in major championship history, while Smith is the first player ever to shoot four rounds in the 60s at the Masters.

Despite Smith’s impressive display, the 2020 Masters belonged to Johnson.

Australia’s Cameron Smith reacts to his shot on the 18th hole during the final round of the Masters. Photo: Getty

The 36-year-old has been a dominant force in golf for some time, without validating his standing, winning at least one PGA Tour event in every season since getting his tour card in 2008.

But it had often been suggested a resume of 23 wins, one major and a FedExCup title were not enough reward for his prodigious talent.

But the 24th victory has cemented his place among the all-time greats as a Masters champion forever more.

The title adds to his 2016 US Open championship after he overcame a hoodoo of failing to convert his previous four 54-hole leads in majors.

Despite being tested early by Im, who got within one shot early, who pulled within two on a few occasions, World No.1 Dustin Johnson has shed the unwanted tag of one-hit wonder, shaking off an early challenge from Australian Cameron Smith to claim the Masters at Augusta National in record fashion.

While Johnson has been a dominant force in golf for some time, winning at least one PGA Tour event in every season since getting his tour card in 2008, it had often been suggested a resume of 23 wins, one major and a FedExCup title were not enough reward for his prodigious talent.

But the 24th win has cemented his place amongst the greats with the 36-year-old a Masters champion forever more. He adds to his 2016 US Open title and overcame a hoodoo of failing to convert his previous four 54 hole leads in majors.

Despite being tested early by the chasing pack, including Im, who got within one shot early, and Smith, who pulled to within two on multiple occasions, Johnson held firm with an incredible 20-under-par 268 total.

Dustin Johnson of the United States plays his shot from the 17th tee during the final round. Photo: Getty

He is the first world No.1 to win the Masters since Woods did so in 2002 and smashed the tournament scoring record of 18 under held jointly by Woods (1997) and Jordan Spieth (2015).

He joined Australian Jason Day and Sweden’s Henrik Stenson as the only players to post 20 under in a major.

Johnson’s 24th PGA Tour win takes him into a tie for 26th on the all-time win list with South African legend Gary Player, the winner of three Masters titles.

Johnson has threatened to win a green jacket for years, having finished in the top 10 in his past four attempts before his victory, including being runner-up to Tiger Woods last year.

This is also Johnson’s 20th top-10 finish in majors with two wins and four runner-ups.

-AAP