Dustin Johnson powers his way to one-shot victory at BMW Championship

As Dustin Johnson waited for a television interview to begin by the 18th green Sunday afternoon, a woman from the gallery hollered: “Class act, Dustin!”

Johnson grinned and waved.

It was a nice capper to a perfect day at the BMW Championship. All those complaints about Cog Hill’s greens melted away under sun-kissed blue skies.

“We opened up parking lots today we haven’t used in years,” said a beaming John Kaczkowski, president of the Western Golf Assn. “This was a great crowd, a great ending and a great champion.”

Exactly four weeks after failing to realize he was standing in a bunker on the 72nd hole of the PGA Championship, Johnson powered his way to a near-flawless final-round 69, good for a nine-under par finish and one shot victory over Paul Casey.

The key: Putting that gaffe, a club-grounding penalty that knocked him out of a playoff, behind him.

“That night coming back from Whistling Straits when we flew home, we had a couple of drinks and a brief discussion — and that was it,” said Johnson’s caddie, Bobby Brown. “The next day he was out on the boat, and the day after that we were playing golf against each other.”

That’s Johnson, a man with a closer’s mentality. Blow a save, pitch no differently the next day.

It also helps that Johnson throws the equivalent of 100-mph fastballs.

“I’m not saying he’s going to be the best player in the world,” Brown said. “He has a long way to go. But I don’t think I’d switch bags with anybody. And I mean, anybody.”

Johnson smashed a driver on the uphill eighth hole, leaving him an 80-yarder that he put within five feet. After making the birdie and walking to No. 9, he high-fived a young girl as a man yelled: “Dustin, this one’s yours!”

Johnson, a tall 26-year-old from Columbia, S.C., with long sideburns, earned sympathy points after he blew a final-round lead at the Pebble Beach U.S. Open and didn’t whine after the Whistling Straits debacle.

Said Brown: “It seems like 99 out of 100 people out there are cheering for him.”

Johnson was tied for the lead when he got to the 427-yard 17th hole. He took the most aggressive line possible with his drive, hammering it over the tree line to “Dustin Johnson land,” as Brown called it.

From 96 yards, he finessed a 54-degree sand wedge to 2½ feet. Then he parred No. 18 with a perfect lag from 40 feet to finish with a total of 275.

Johnson celebrated by giving Brown a quick hug.

“To finally get it done,” Johnson said, “after all the things I’ve gone through this summer, it can’t feel any better.”

Said Brown: “There wasn’t any stress out there. During the last two holes he was singing some Usher song.”

Johnson’s fourth PGA Tour victory moved him from 16th to second in the FedEx Cup standings, meaning he can claim the $10-million top prize by winning the season-ending Tour Championship in two weeks.

The same can be said for Matt Kuchar, who’s first in points, and Charley Hoffman, Steve Stricker and Casey, who round out the top five.

“The $10 million,” Johnson said, “would look nice in the bank account. I like seeing them zeroes.”

Tiger Woods shot a 70 and tied for 15th at 283, failing to move into the top 30 in the standings. He won’t play in the Tour Championship, the first time as a pro he has not been eligible for a tournament.

The Associated Press contributed to this report.