AKRON, Ohio — Tiger Woods returned to Firestone and had his lowest opening round of the year at the Bridgestone Invitational.

It was barely enough to keep pace.

Conditions were so soft and vulnerable Thursday that Kyle Stanley opened with a 7-under 63 among the early starters, and even that might not be enough to stay in the lead by the end of the first round. Only nine players from the 36 who teed off early were over par.

Woods made bogey from a fairway bunker on his final hole for a 66. He made five birdies, including a 50-foot putt from just short of the 18th green as he was making the turn. Woods is an eight-time winner at Firestone, which is hosting this World Golf Championship for the last time.

For such an easy day of scoring, Woods said he "fought" for a good score.

"It's nice to shoot rounds like I did at the Open and like I did today, put together rounds where I may not feel the best, but I'm able to post a score," Woods said. "That's how you win golf tournaments. You're not going to have your best all four days, and it's a matter of that bad day being 2-, 3-under par instead of being 2-, 3-over par. And then everyone has their hot days."

Stanley was plenty hot, going out in 30 on the back nine and reaching 7 under through 11 holes before settling for a 63.

Patrick Cantlay had a 64, while Rory McIlroy, Jason Day and Anirban Lahiri were among those at 65. Day played in the same group as Woods, and they were tied until Woods drove into a bunker on the par-4 ninth, came up short of the green and missed a par putt from just inside 10 feet.

"Once you find the confidence, then he's not too far away. He's not too far away from going on a pretty big tear here," Day said. "We just hopefully stay out in front of him."

Woods is coming off a tie for sixth at the British Open, where he had the lead for about 30 minutes in the middle of the final round until he fell back with a double bogey. He took a vacation in Switzerland and showed up at Firestone for nine holes of practice on Wednesday.

But he knows this course as well as anyone, already holding the PGA Tour record for most victories on the same golf course.

"I've had so many great memories here," Woods said. "Hopefully, I can have one more."

Dustin Johnson, the world No. 1 coming off his third victory of the year last week at the Canadian Open, was among those playing in the afternoon. Johnson won at Firestone two years ago right after capturing the U.S. Open. McIlroy won in 2014 in between winning two straight majors.

McIlroy played in the group ahead of Woods and struggled to get the ball in play over the first half of his round. He figured it out, which he had to on a day like this.

"You can't find this golf course any easier than we had it today," McIlroy said. "It's soft. It's probably the softest I've ever seen it. Usually you have to hit your ball in the fairway here, but even I missed a few shots in the rough and it seemed like you could even get your ball to stop on the greens, even if they're tucked behind bunkers. ... So you needed to take advantage of the conditions today. It looked like most of the guys have done that, which is good."

Jordan Spieth was not among them. After an early birdie, Spieth was 3 over through 14 holes until two later birdies gave him a 71.