AKRON, Ohio (AP) — Some golfers need to trust their swing. Some need to trust their judgment.

Webb Simpson grabbed a surprising first-round lead at the Bridgestone Invitational by trusting his caddie.

Playing Firestone Country Club for the first time, Simpson relied on caddie Paul Tesori to help guide him around in a round of 6-under-par 64 on Thursday.

"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."

Tesori has caddied for the likes of Vijay Singh and Jerry Kelly and is also an accomplished player.

Even veterans who seem to know every blade of grass on the course can benefit from a good partner out there. Seven-time Bridgestone winner Tiger Woods proved that with the help and counsel of caddie Joe LaCava.

"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 a 66, his best opening round at the course since a 66 on the way to a win 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 but closed with a bogey. He hasn't won this season, calling his year "encouraging and frustrating."

"I do feel like I'm getting better," he said. "I just don't have the results this year to show it."

Stenson birdied the first hole and then pounded a fairway wood 243 yards to inside 4 feet to set up an eagle on the second.

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 he 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.

It's hard to quantify how Woods has dominated at Firestone since he won what was then called the NEC Invitational in his first three appearances (1999-2001). He then had three top-five finishes before reeling off victories in his next four starts at the Bridgestone (2005-2009). He missed the 2008 tournament while recovering from knee surgery.

In his 13 starts at the course, he has 11 top-10 finishes — and has earned more than $9.5 million.

"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.

This time Bradley opened with a workmanlike 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 that includes 49 of the top 50 players in the world rankings were Furyk, Jason Dufner, Bubba Watson, Rickie Fowler, Bill Haas and Luke Donald.

Fowler spoke 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.

Frequently accused of being too hard on himself, McIlroy looked at the positives.

"I'm just trying to enjoy myself this week, enjoy my golf, play with a bit more of a smile on my face," he said.

Then he added, "You have to have a positive attitude out there to play well. But saying that, it's easier to smile when you play well."

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