SHEBOYGAN, Wis. - Martin Kaymer's name is etched on the side of the Wanamaker Trophy.

A far more compelling image from this PGA Championship was Dustin Johnson taking one last look at his scorecard Sunday before turning over his pencil to use the eraser on his final hole.

The 5 turned into a 7.

It kept Johnson out of a playoff, which Kaymer won over Bubba Watson, all because of a tiny patch of sand well right of the 18th fairway where Johnson gently placed his 4-iron behind the ball, unaware that it was part of a bunker.

"It never crossed my mind that I was in a sand trap," Johnson said.

The resulting two-stroke penalty for grounding his club in a bunker — outside the ropes, where thousands of fans had been walking all week — turned a thrilling final hour into a controversial finish that will be debated for years.

Video   Dustin Johnson's penalty explained Aug. 16, 2010: Mark Wilson, co-chairman of the PGA Rules Committee explains Dustin Johnson's two stroke penalty in the final round.

In a strange season of golf, from Tiger Woods' sex scandal to unlikely winners in the majors, this one topped them all.

Whistling Straits has so many bunkers — more than 1,000 — that not even architect Pete Dye can count them all. Perhaps it was only fitting that one of them played such a pivotal role in the season's final major.

"It was very tough to see what is a bunker and what is not a bunker," said Kaymer, who won the three-hole playoff with a tap-in bogey. "I think it's very sad he got two penalty strokes. He played great golf. He's a very nice guy."

Kaymer won his first major in a PGA Championship that will be remembered as much for the guy who tied for fifth.

It was the cruelest end to a major since Roberto de Vicenzo signed for a higher score than he actually made in the 1968 Masters, which kept him out of a playoff against Bob Goalby.

Johnson had no excuses. The peculiar rule about every bunker being treated the same had been posted in the locker room all week. And he offered none when a PGA rules official stopped him walking off the green and said, "We've got an issue."

His first reaction when told he might have grounded his club in a bunker: "What bunker?"

Johnson didn't even bother going to the TV truck to study the replay. He knew he grounded the club. He just didn't know that he was in the edge of a bunker, figuring it was grass that had been killed under so much foot traffic.

Video   Watson gets emotional after PGA Aug. 16, 2010: Bubba Watson looks at the bright side of his second place finish and is excited he made the Ryder Cup team.

"The only worse thing that could have happened was if I had made the putt on that last hole," Johnson said.

Thinking he had a chance to win, Johnson missed a 7-foot par putt on the 18th to seemingly slip into a three-man playoff. Instead, the two-shot penalty turned his 71 into a 73, and instead of going to a playoff for redemption from his U.S. Open meltdown, Johnson tied for fifth and headed home.

As Johnson was leaving the course, Kaymer was coming up clutch again.

The 25-year-old German holed a 15-foot par putt on the 18th hole in regulation for a 2-under 70 to join Watson (68) at 11-under 277. One shot behind in the playoff, Kaymer made another 15-foot putt for birdie on the par-3 17th, then watched Watson implode.

Watson went from the right rough into the water, then over the green into a bunker. His bunker shot hit the flag, and he tapped in for double bogey. Kaymer chipped out after seeing Watson go in the water, and he hit 7-iron to 15 feet for a two-putt bogey.

"I don't realize what happened," Kaymer said. "I just won my first major. I've got goose bumps just talking about it."

Kaymer earned $1.35 million, went to third in the Ryder Cup standings for Europe and moved to a career-best No. 5 in the world.

PGA CHAMPIONSHIP Excerpt from “Supplementary Rules of Play” 1. Bunkers: All areas of the course that were designed and built as sand bunkers will be played as bunkers (hazards), whether or not they have been raked. This will mean that many bunkers positioned outside of the ropes, as well as some areas of bunkers inside the ropes, close to the rope line, will likely include numerous footprints, heel prints and tire tracks during the play of the Championship. Such irregularities of surface are a part of the game and no free relief will be available form these conditions. Note 1: The sand area in front, left and behind No. 5 green in the later water hazard is NOT a bunker (do not move stones). Note 2: Where necessary, blue dots define the margin of a bunker.

Watson was only disappointed for a few minutes until learning he had played his way onto the Ryder Cup team.

For Johnson, this might take far longer to recover from than the U.S. Open, where he had a three-shot lead going into the final round, took triple bogey on the second hole and shot an 82.

The final major of the year proved to be the most thrilling over the final hour, even with Woods long gone before all the excitement began. Woods closed with a 73 and tied for 28th.

Six players had a share of the lead at some point Sunday, and six players were separated by one shot over the final 30 minutes.

That included Rory McIlroy, the 21-year-old from Northern Ireland who was trying to become the youngest major champion in 80 years. He had a 20-foot birdie putt on the final hole to join the clubhouse leaders at 11 under, only for the putt to turn away.