KIAWAH ISLAND — A tiny leaf played a big role Sunday in the PGA Championship.

Sweden’s Carl Pettersson may not have caught Rory McIlroy, but he certainly would have been in better position had it not been for the two-stroke penalty he incurred on the first hole of the final round.

Pettersson’s tee shot landed just inside the hazard line, and during his backswing on the approach shot he clipped a small leaf, resulting in a rules violation for moving a loose impediment in a hazard.

Instead of a par, Petterson made a double bogey on the hole and found himself four shots behind McIlroy.

And instead of finishing in second place all by himself and winning $865,000, Pettersson tied for third and won $384,500. The leaf cost him $480,500.

Petterson posted a final-round score of 72. In addition to the double bogey, he made two bogeys and four birdies and tied with defending champion Keegan Bradley, Justin Rose and Ian Poulter.

“I’ve got to take it on the chin, but it’s one of those stupid rules. I didn’t even realize I moved it because I’m trying to hit the ball,” said Pettersson.

Pettersson said he didn’t think about the leaf until a rules official came to him and told him he thought there was a penalty.

Pettersson found out for sure on the fourth hole after it had been reviewed on video. Pettersson said he asked the rules official “14 times if they were 100 percent.”

“If you’re in a hazard, you can actually touch the grass. You just can’t put any weight on it,” Pettersson said.

“But it made me more motivated. I got a little fired up and made (three) birdies in a row.”

For Pettersson, it brought back memories of a similar incident in the final round of the 2010 Heritage when Brian Davis penalized himself for the same infraction while trying to play from a hazard at Harbour Town’s 18th hole, giving Jim Furyk the win.

“I guess the rule is there so you don’t knock anything out of the way on the backswing to make sure you’re able to hit it. It’s one of those unfortunate things. I wish it was different, but it is what it is.”