(REUTERS) - Top seed Dustin Johnson birdied the final hole to move into a three-way tie for the lead after the opening round of the Tour Championship in Atlanta on Thursday (Sept 22).

The long-hitting Johnson, a three-time winner on the 2015-16 PGA Tour, holed out from four feet at the par-five 18th to card a four-under-par 66 on the East Lake course.

Fellow American Kevin Chappell and Japan's Hideki Matsuyama also carded 66, one stroke better than Australian world number one Jason Day, South Korean Kim Si-woo and American Kevin Kisner.

Johnson, the US Open champion, began the season-ending Tour Championship atop the FedExCup rankings.

If he wins on Sunday, he is also guaranteed to clinch the PGA Tour's FedExCup and a US$10 million (S$13 million) bonus.