KIAWAH ISLAND -- Carl Pettersson admits his play in golf's major championships hasn't been noteworthy.

"I think I've had two top-10s," he said. "But I'd love to have a chance and see what happens."

He's off to a good start.

Back in South Carolina, where he won the RBC Heritage presented by Boeing back in April, Pettersson continued his push to play better four times a year. He posted a 6-under-par 66 on Thursday to open the PGA Championship at Kiawah Island's Ocean Course and leads a group with solid major championship credentials.

Rory McIlroy, the 2011 U.S. Open champion, opened with a bogey-free 67. John Daly, more than 20 years removed from his PGA Championship victory at Crooked Stick, is among a group at 4 under that includes defending champion Keegan Bradley and past U.S. Open champions Geoff Oglivy and Graeme McDowell. Tiger Woods is another shot back after opening with a 69.

The big names took advantage of a benign Pete Dye design early in the day. Soft conditions and little wind weakened the course's defense.

"It still is a very good and a very tough golf course, but I think we had it under some of the easier conditions you can probably get," Pettersson said.

A lower number was out there. Dutch golfer Joost Luiten reached 8 under but bogeyed his final four holes to shoot 68. He said he might have gotten too aggressive late in the round.

Conditions pushed players to attack.

"You have to realize there's going to be a lot of scoring opportunities out there," McIlroy said. "And you're going to have to take a few of them."

McIlroy jumped on another major championship layout when it played soft, shooting a U.S. Open-record 268 at Congressional in 2011 to win by eight shots. But the consensus Thursday was that the Ocean Course's kindness wouldn't last, that the wind would inevitably blow and send scores askew -- a return to the layout's treachery at the 1991 Ryder Cup.

Conditions worsened slightly in the afternoon. But several players still tamed a breezy back nine, including Sweden's Alex Noren, who is a shot back at 5 under.

Swedish-born Pettersson won for the fifth time on the PGA Tour when he grabbed the tartan jacket at Harbour Town in April. A U.S. citizen since January, Pettersson is not eligible for the American Ryder Cup team -- a player has to be born here to be eligible. And he's not a member of the European Tour, so can't earn points toward the European Ryder Cup team. He's hoping to play his way onto the European team as a captain's pick.

Pettersson said his game was close in 2006 and 2008, and that he watches the event on television and wants to participate.

In the meantime, he is working to solve the majors. His best finishes are a tie for sixth at the U.S. Open in 2008 and a tie for eighth at the British Open in 2006.

"You have to be on the whole week because of the setup of the golf courses, and I guess I haven't done that enough," Pettersson said. "Maybe I needed a little bit more experience of playing tougher golf courses."

Dye's Ocean Course -- a links look that doesn't play true to the style -- has a reputation as one of the country's toughest courses. On Thursday, it backed down. Pettersson, a longtime disciple of the long putter, made birdie on four of his first seven holes and didn't drop a shot.

"I knew it was get-able today," he said.

Woods thought scores would plunge after watching playing partner Bradley start birdie-eagle and seeing the red numbers dot the leaderboard. But Woods' modest round was good enough to remain in the top 15 after Day 1.

Crosswinds in the afternoon kept scores manageable.

"I said, 'Oh boy, it's going to be one of those days where everybody shoots 6, 7, 8 under par," Woods said. "But the wind kicked up a little bit, and it changed things quite a bit."