Dustin Johnson is among three tied for the lead after the opening round of the Tour Championship as the big names started well.

The American started with a four-under 66 to be alongside countryman Kevin Chappell and Japan's Hideki Matsuyama atop the leaderboard at East Lake.

Johnson, who started the season-ending tournament atop the FedEx Cup standings, birdied the 18th to earn a share of the lead. The U.S. Open champion had three birdies on the front nine and another on the 12th, before a bogey at the next slowed his charge.

World number one Jason Day (67), Jordan Spieth (68) and Rory McIlroy (68) all made bright starts in Atlanta, Georgia.

Day, who has recently battled a back injury, is tied for fourth with Kevin Kisner and South Korea's Kim Si-woo.

Spieth and McIlroy had mixed rounds but are alongside Paul Casey and Justin Thomas in a tie for seventh at two under.

After a bogey-double bogey start, Spieth quickly found himself three over, but he recovered and finished birdie-birdie.

Spieth told the Golf Channel: "Rory started that way at Deutsche Bank this year just a few weeks ago and ended up winning the tournament. I think he might have been three over through four.

"So, I told myself to stay patient. This is a golf course where I feel very comfortable on the greens and very comfortable in general, feel comfortable on this type of grass so I made a couple of long putts on the next two holes to settle me down and we got it to even by the turn.

"Obviously I'm very pleased because that could have gone south quickly."

McIlroy endured a rollercoaster round that featured a hat-trick of birdies, back-to-back double bogeys and four straight birdies from 12 to 15.