Dustin Johnson, Kevin Chappell tied for lead at the Tour Championship

Dustin Johnson made one mistake that suddenly put some intrigue into the final day of the PGA Tour season — the Tour Championship and the FedEx Cup.

Johnson clipped a tree trying to get out of the rough on the 17th hole and made double bogey, and only a birdie on the final hole at East Lake on Saturday allowed him to shoot a one-under-par 69 and regain a share of the lead with Kevin Chappell.

Chappell went from a four-shot deficit on the front nine to a one-shot lead when he made a 10-foot birdie putt on the 17th and Johnson made his double bogey. Chappell, still looking for his first PGA Tour victory, shot a 68.

They were at eight-under 202.

Rory McIlroy and Ryan Moore each had a 66 and have different prizes at stake Sunday. They were two shots behind, still very much in the game after wondering most of the steamy afternoon if Johnson was going to give anyone a chance.

Johnson still has control of the $10-million bonus for winning the FedEx Cup. He only has to win or finish second alone in the Tour Championship to win the cup. McIlroy, five shots behind at the start of the third round, would have to win the Tour Championship and have Johnson finish in a two-way tie for second.

On this course, and after the way Saturday finished, it no longer looks like such a stretch.

“I just need to try and win this golf tournament, and whatever happens after that, happens,” McIlroy said. “It would just be great to try to win the Tour Championship, and if the chips fall my way, then so be it.”

Moore went out in 31 until he was slowed by a pair of bogeys, though very much in the mix just two shots out of the lead. The mystery is whether anything he does on Sunday — even if that means a victory — is enough for Davis Love III to use his last captain’s pick on Moore for the Ryder Cup.

“I came here this week to win a golf tournament, and I’m 100 percent focused on that,” Moore said, adding that the Ryder Cup is “completely out of my control.”

And that’s how the last day is shaping up for everyone — post a score and see where it leads.

Hideki Matsuyama of Japan had a 68 and was three shots behind, while Jason Dufner had a 66 was four back.

European Open cut to three rounds

French golfer Alexander Levy took a four-shot lead going into the third and final round of the European Open after the event was shortened to 54 holes.

Morning fog delayed the start of play again for the third day, forcing organizers to cut the event to three rounds.

Levy, who was at 17 under when play was halted on Friday evening, completed the final hole of his second round with a par on the ninth. Eight birdies earlier gave him a flawless 63 to stay 17 under after his course-record opening 62.

Michael Jonzon of Sweden also carded a 63 to move to second at 13 under, one shot ahead of England’s Ross Fisher, who carded 65-65.

Bernd Wiesberger of Austria posted a 68 to drop into a tie for fourth with Germans Florian Fritsch and Martin Kaymer, all at 11 under. Levy finished in a tie for seventh at last week’s Italian Open, and is seeking his third European Tour title and first since the 2014 Portugal Masters.