Augusta, Nov 16 : World number one Dustin Johnson won the Augusta Masters by five strokes as he finished with a record-breaking low score of 20 under par. Johnson shot a final-round 68 to hold off Cameron Smith of Australia and South Korea's Sungjae Im on Sunday. They both shot 69 to tie for second on 15-under, however in the end, had no answer to Johnson, who played the final 13 holes bogey-free. Justin Thomas was fourth at 276, with Rory McIlroy and Dylan Frittelli tying for fifth. Defending champion Tiger Woods carded a 10 on the par-three 12th but recovered with five birdies to finish one under. Playing in his 11th Masters, Johnson owned the event which was delayed by seven months and held without patrons because of the Covid-19 pandemic. The foundation for the victory of the 36-year-old was, however, set with an opening 65 that gave him a share of the lead, and he had another 65 on Saturday to become the first player in Masters' history to achieve such a feat. He made a par-save at two and birdied the third but successive bogeys followed as Im and Smith applied pressure. Johnson, however, recovered with a birdie on the par-three sixth as Im made his first bogey of the day and another birdie at eight saw the American lead Smith by two as he headed to the back nine. Smith, in the group ahead, bogeyed 11 to once again hand Johnson a three-stroke advantage. Johnson then scored a birdie at 13 and made it three in a row through 14 and 15 to accelerate to 20 under par. "I was nervous all day," Johnson said as per the tournament's official website. "But I felt I controlled myself very well, controlled the golf ball very well in difficult conditions," he added. Johnson's superb performance saw him beat the record lowest winning score of 18 under par set by Woods in 1997 and Jordan Spieth in 2015. The world number one, however, could enjoy what would have been a magnificent reception from the gallery at the 18th green. Instead, he received a round of applause from the few people allowed on-site due to Covid-19 restrictions. "Welcome to the club," Bubba Watson, wearing his Green Jacket, told Johnson by the 18th green. "I always dreamed of having one of those," Johnson responded. The American has become the first world number one to win the tournament since Woods in 2002. "I want to play - it keeps getting shorter - eight, nine, maybe 10 years, then hang out with my kids and Paulina," Johnson said. "So until then, I'm going to work my butt off to be as good as I can," he added. /IANS