The American golfer made six birdies and one eagle on his way to a final-round 63 at TPC Boston, finishing 30-under for the competition and 11 shots ahead of Harris English.
Johnson’s victory — his 22nd on the PGA Tour — once again means he is the world No. 1 in golf, and is the fifth different player to occupy the position in 2020.
“I’d like to stay there for a little while,” said Johnson, who was last world No. 1 in May 2019.
“Obviously it’s been jumping around a bunch here the last few months, but the last time I was number one, I think I stayed there for quite some time, and that’s another goal of mine … to see how long I can stay at No. 1.”
Johnson, who tied second at the PGA Championship last month, recorded rounds of 67, 60, 64, before completing his eight-under 63 in near-darkness after a storm delay caused a temporary halt to play.
The 2016 US Open winner’s 30-under score was just one off the lowest over four rounds in PGA Tour history currently held by Ernie Els, who set it at Kapalua in 2003, and by Justin Thomas at the Sony Open in 2017.
Johnson has now won at least once in every one of his 13 PGA Tour seasons and, following his victory on Sunday, sits atop the FedExCup standings.
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The Northern Trust was the first of three events that make up the FedEx Cup playoffs. The top 125 players in the FedExCup standings qualified for the event in Boston, Massachusetts.
The top 70 players now advance to next week’s BMW Championship, which in turn will determine the 30 players who will compete in next month’s Tour Championship in Atlanta.