Dustin Johnson watches his approach shot on the eighth hole Sunday during the third round of the Tour Championship. Johnson opened a five-shot lead with a 6-under 64. John Bazemore/Associated Press

ATLANTA — Dustin Johnson watched his opening drive sail long and fall gently to the right, just like he imagined. So did the next drive. It was like that all day at East Lake, and the outcome was predictable.

Johnson is playing the best golf and looks tougher than ever to beat.

When he finished with a 10-foot birdie Sunday, Johnson matched the low round with a 6-under 64 to build a five-shot lead over Justin Thomas and Xander Schauffele in the Tour Championship, leaving him one round away from the FedEx Cup and its $15 million prize.

“I’ve got a lot of confidence in everything I’m doing right now,” Johnson said.

A quick fix on the range the previous evening was all he needed to get straightened out. Johnson missed only three fairways, and not by much. He putted for birdie on all but three holes and made seven of them.

“He’s showcased what he can do,” Schauffele said. “If he does what he normally does, it’s going to be almost impossible to catch him.”

Normal these days for Johnson must be daunting for everyone else.

He was at 19-under par, making this his four consecutive start with at least a share of the 54-hole lead. He converted one of those into an 11-shot victory at the TPC Boston. He lost to a 65 by Collin Morikawa in the PGA Championship and to a 65-foot putt by Jon Rahm in a playoff last week in the BMW Championship.

“We’re going to need Dustin to throw us a bone and not have a good day,” said Rahm, who was six shots back.

Johnson knows better than anyone that it’s not over. He had a six-shot lead in Shanghai three years ago and failed to win, though he had a new set of irons and was coming off a five-week break. He also had a five-shot lead at The Northern Trust two weeks ago and obliterated the course and the field to win by 11.

“If he hits the ball like everybody knows he can and the way he’s putting … I haven’t seen him putt that well in a long time,” Harris English said. “It’s hard to stop.”

Only four players have a reasonable chance of catching him.

Schauffele, who won the Tour Championship three years ago, dropped only one shot on the front nine and finished with a 10-foot birdie putt for a 67 that puts him in the final group with Johnson.

Thomas missed a 16-inch par putt on the 10th hole with a careless tap-in, but bounced back with a 25-foot birdie putt on the toughest par 3 at East Lake and made two more birdies for a 66.

They were at 14 under.

“DJ is clearly playing well. It wasn’t easy today,” Thomas said. “It’s still East Lake. But anything can happen around this course. You can shoot 63 or 64 and you can shoot 73 or 74 very easily. I just need to hope that tomorrow is my 63 or 64.”

Rahm has had a wild week. He opened with a 65, followed with a 74 and bounced back with a 66. He played bogey-free, and his round only felt better when he finished with two birdies.

“The one good thing I have going for me is we’re here to win, so tomorrow is a green light for everything,” Rahm said.

Morikawa rallied with five birdies on the back nine to salvage a rough start for a 67. He was seven behind.

The FedEx Cup has been on Johnson’s mind ever since he squandered a great chance to win it in 2016. He went into the final round that year tied for the lead and then couldn’t find a fairway, closing with a 73. He still had a chance to win the FedEx Cup because it was based on points back then, but the only one player who could have beaten him, Rory McIlroy, holed a shot from the fairway on the 16th for eagle and then won in a three-way playoff.

Johnson moves on from wins and losses, no matter how high or how crushing. Even so, he thinks about that day, mainly because the list of FedEx Cup champions is filled with big names and his isn’t among them yet.

“To be the FedEx Cup champion is something that I want to do. It’s something that I want on my resume when I quit playing golf,” he said. “Yeah, it means a lot to me. So yes, I do want to win this tournament. … I had a chance to win it a few years ago. I couldn’t control winning by my golf. Tomorrow, I do.”

McIlroy won’t be in the mix this year. He was walking off the 17th tee and looked back at Johnson heading to the 14th, a 512-yard par 4 and the toughest at East Lake. Johnson already was 10 shots ahead of him, and then smashed a drive down the fairway and made a 15-foot birdie putt.

McIlroy birdied the 17th to salvage a 70. He was 11 shots back.