First came an 82 on the final day of the U.S. Open. Then came a crushing blow at the PGA Championship, when he was denied a spot in the playoff for not realizing he was in a bunker and touching the sand with his club on the final hole.
Resilient as he is powerful, Johnson kept coming back.
The payoff came Sunday in the BMW Championship, when the 26-year-old American was flawless on the back nine at Cog Hill and made up a three-shot deficit against Paul Casey to win for the second time this year. Playing in the final group for the fourth time since June, Johnson closed with 2-under 69 for a one-shot victory.
"To finally get it done, especially after all the things I've gone through this summer ... it can't feel any better," Johnson said. "I played really good golf today. I didn't make as many birdies as I would have liked, but I made just enough."
Tied for the lead, Johnson knew the 17th hole might be his last good chance. He pulled driver and smashed his tee shot over the trees with a slight fade, the ball landing in the fairway and leaving him a sand wedge that he hit within 2 feet for a tap-in birdie.
The Pebble Beach winner in February, Johnson has quickly emerged as one of the game's rising stars. He now goes to the Tour Championship at No. 2 in the FedEx Cup standings.
One player he won't have to beat at East Lake is Tiger Woods. The world's No. 1 player sputtered at the start and shot 70 to tie for 15th, not nearly enough to move into the top 30 in the standings and advance to the FedEx Cup finale.
It's the first time as a pro that Woods hasn't been eligible for a tournament.
"That's just the way it is," Woods said. "I didn't play well early in the year, and I didn't play well in the middle of the year."
Woods played with Phil Mickelson for the first time all year, and Lefty buried him. Mickelson closed with 67 and tied for eighth, his first top 10 since the U.S. Open.
Casey shot four rounds of 69 to finish alone in second. The consolation was moving up to No. 5 in the FedEx Cup standings, and the top five players at East Lake only have to win to collect the biggest payoff in golf.
The biggest blow to Casey on the back nine was hooking his tee shot into the bushes on the par-5 15th. He made his third consecutive bogey to fall into a tie, and Johnson outplayed him from there.
With the 70-man field at Cog Hill narrowed to the final 30, the BMW Championship offered plenty of drama away from the leaders.
Charlie Wi appeared set for his first Tour Championship until making bogeys on the last two holes, missing a 12-foot par putt on the final hole. That moved Bill Haas up to No. 30.
Then came Matt Kuchar, who needed a birdie for any hope of getting into a playoff at Cog Hill. He ran his putt 31/2 feet by the hole, then missed it coming back. Kuchar was in a two-way for third, and the bogey moved him into a three-way tie for fourth. That allowed K.J. Choi to crack the top 30.
Ryan Moore, the 54-hole leader, was alone in third place when he sent his second shot over the 18th green. He smartly played away from the pin to avoid chipping into the water and took his bogey, which kept him in the top 30.
The 30th and final spot went to Bo Van Pelt.