AKRON, Ohio — So much for course knowledge.

Webb Simpson, playing his first competitive round at Firestone Country Club, shot a 6-under 64 on Thursday to take a one-stroke lead in the Bridgestone Invitational.

It all came down to trust.

"Well, I knew it all through my caddie (Paul Tesori), who's been here so many years," Simpson said. "I just kind of had to listen to him."

Tesori has caddied for years on tour, for Vijay Singh and Jerry Kelly, in addition to being a pro himself.

"It's hard for us players to listen to our caddies, but he basically showed me where to go yesterday and told me where to hit it, where the lines were, what clubs to hit," said Simpson, the 2012 U.S. Open champion. "I didn't feel like it was my first time because he has so much experience here."

Seven-time Bridgestone winner Tiger Woods did not have to rely so much on the man on his bag, Joe LaCava, while shooting a 66. Woods has 11 top-10 finishes in his 13 starts at the course, so he clearly knows where to go.

Still, he needed his counsel from time to time.

"I hit a lot of good shots. I had a really good feel for the distance today, and Joey and I really read the wind right today," Woods said after his best opening round at the course since another 66 spurred him to a one-shot victory in 2005. "We changed a lot of shots out there, and we both had a really good handle on what we were doing feel-wise with the wind."

Henrik Stenson was alone in second with a 65. Defending champion Keegan Bradley, Ryan Moore and Chris Wood, another first-time entrant, matched Woods at 66.

Simpson had six birdies in an eight-hole span.

There was only one glitch.

"I wish I didn't bogey the last hole," he said after missing the green on the par 4 and failing to get up and down. "It's one area I've got to get better at. When I'm between clubs, hitting more club and swinging easy is where I've been struggling.

"You know, there's always something to work on."

Simpson hasn't won this season. He called his year "encouraging and frustrating."

"I feel like I've let a couple of tournaments go that maybe I should have closed out," he said.

Stenson started out birdie, eagle — hitting his second shot 243 yards on the par-5 hole to inside 4 feet. He slowed down from there, parring every hole except for birdies at the 11th and 12th holes.

He had more problems with his outfit than the course. He was breaking in a new pair of shoes and felt a blister coming on at the turn, so had to switch to an older pair that didn't necessarily fit with his ensemble.

"They might not match the outfit perfectly, but it felt like I had socks on compared to the other ones," he said, grinning.

Woods would have a nice career if only World Golf Championship events, such as the Bridgestone, counted. He won three in a row (1999-2001) at Firestone, then had three top-five finishes before reeling off victories in his next four appearances (2005-2009), and missing the 2008 tournament while recovering from knee surgery.

In 41 WGC starts, he has 32 top-10 finishes.

There's something about Firestone that brings out the best in him.

"Luckily, over the years I've taken advantage of it," he said. "I have played well and I've scored well, and I've won my share of tournaments here."

Bradley won the Bridgestone a year ago when he shot a closing 64, and Jim Furyk, who had led all week, double-bogeyed the closing hole.

Bradley put together a workmanlike, efficient 66 that didn't include a bogey.

The 2011 PGA Championship winner doesn't want to stress out on defending his title.

"No, it's business as usual," he said. "I just want to not put too much pressure on myself to do anything crazy. I know this golf course fits me, so to let the course come to me is big here."

Another shot back at 67 in the star-studded field were Furyk, Jason Dufner, Bubba Watson, Rickie Fowler, Bill Haas and Luke Donald.

Fowler was speaking for a lot of players when he said that there are a lot of similarities between Firestone and Oak Hill, the site of the PGA Championship next week.

"If the course stays dry and it starts to firm up through the weekend, it's very comparable as far as you've got to drive the ball well and position yourself off the tee," said Fowler, who practiced at Oak Hill on Monday. "It's a great warm-up here, but obviously this is one of our bigger weeks of the year, too. Two great weeks, back-to-back, and two great golf courses."

While the world's top-ranked player, Woods, was in prime position, that wasn't necessarily the case for Nos. 2 and 3.

Phil Mickelson, coming off his dramatic victory at the British Open two weeks ago, struggled with his concentration and came in with a 72.

"Tonight I'll get a little bit more rest and try not to do too much and see if I can come out tomorrow a little bit more focused," he said.

He missed two par putts inside 3 feet on consecutive holes early in his round.

Rory McIlroy shot a 70. The defending PGA champion is winless this year.

"I just threw a few shots away around the greens," he said. "You know, you start to save shots there and all of a sudden you're 3- , 4- or 5-under par."