Dustin Johnson celebrates with the FedEx Cup Trophy on Monday in Atlanta, Georgia. Photo: IC

Dustin Johnson secured a three-shot victory at the Tour Championship to claim his first FedEx Cup title and a $15 million payday on Monday as he capped a PGA Tour season that saw him return to the top of the world rankings.

The final event of the 2019-20 PGA Tour campaign looked poised for a drama-free finish with Johnson starting the day having a five-stroke cushion at East Lake Golf Club.

But the 36-year-old American needed almost all of it, carding a final-round two-­under 68 to fend off 2017 FedEx Cup champion Justin Thomas and Xander Schauffele, who both closed on four-­under 66.

Johnson, who began the week at 10-under as a result of the Tour Championship's FedEx Cup scoring system, finished with a winning total of 21-under 269 to earn his 23rd career title and third this season, all coming after the COVID-19 restart.

Having narrowly missed out on the FedEx Cup ­title four years ago when Northern Ireland's Rory McIlroy pipped Kevin Chappell and Ryan Moore in a three-man playoff at the Tour Championship, Johnson, who rarely speaks about his goals, did not hide the fact that winning it was a career objective.

Certainly Johnson played like a man on a mission, finishing first, second and first in the three playoff events.

"I wanted to be a FedEx Cup champion. It was something in my career I would like to be and today I got the FedEx Cup," said Johnson.

The only thing Johnson did not win this season was a major title although he came close by finishing runner-up at last month's PGA Championship.

But because of a schedule shakeup created by the COVID-19 outbreak, there are still two golf majors to be contested before the end of 2020, the Masters in November and the US Open from September 17 to 20 where Johnson is sure to be the red-hot favorite. "I am probably playing the best I have ever played," said Johnson. "I really feel like everything is dialed in.

"I just have a lot of confidence in every part of my game right now."