LEMONT, Ill. -- Maybe now everyone will believe Dustin Johnson when he says he is over a summer of Sunday disappointments.
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 for more.
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 a 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."
He made three birdies, none more important than the last one.
Tied for the lead, Johnson knew the 17th hole might be his last good chance. He pulled his 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.
"I knew I needed to hit a good tee ball because it was going to be my best chance of making a birdie," he said. "I was just trying to cut a drive, hold it against the wind and get it around the corner a little bit. And I hit it perfect."
Equally impressive was the 18th, where Johnson ripped another drive to set up a conservative par.
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, with a clear shot at the $10 million bonus.
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 a 67 and tied for eighth, his first top 10 since the U.S. Open. It was the 26th time the world's best two players have been in the same group, and the record now stands at 11-11-4.
"He certainly brings out the best in me, and I enjoy being paired with him," Mickelson said.
Casey was left off the Ryder Cup team despite being No. 9 in the world when European captain Colin Montgomerie made his three picks. He had a great chance to make Montgomerie look foolish, building a three-shot lead on the back nine, only to throw it away with three straight bogeys. Casey had three chances from the fairway coming in, but didn't give himself a birdie opportunity inside 25 feet.
Asked if he was motivated by not being picked, Casey smiled and said, "Yes."
But he wouldn't say much more.
"I can't go there, unfortunately," the Englishman said.
He 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, which can be reached in two. He made his third straight bogey to fall into a tie, and Johnson outplayed him from there.
"It was myself against the golf course, 72 holes, and I played it one shot worse than Dustin Johnson," Casey said.
With the 70-man field at Cog Hill narrowed to the final 30, the BMW Championship offered plenty of drama away from the leaders.
Then came Matt Kuchar, who needed a birdie for any hope of getting into a playoff at Cog Hill. He ran his putt 3 1/2 feet by the hole, then missed it coming back. Kuchar was in a two-way tie 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. If Moore had made double bogey, he would have fallen out of the Tour Championship.
The 30th and final spot went to Bo Van Pelt.
Johnson earned a small measure of redemption. He likely moves to No. 12 in the world with his fourth career victory.
"I know I've had some failures -- I don't know if I'd call them failures -- I've had a few mishaps," Johnson said. "To come back and get it done, I'm very proud of myself. I think I've handled everything very well, and now I've got to look forward to two weeks from now."