Tiger Woods made an excellent start to his bid for an incredible ninth WGC-Bridgestone Invitational in Akron on Thursday, while Rory McIlroy is also right in he mix after shooting a five-under 65 to sit three off leader Ian Poulter.
Poulter shot an eight-under-par 62, just one outside the course record, which gave him a one-shot lead over Americans Kyle Stanley and Rickie Fowler. On a day of low scoring, Spain's Jon Rahm also carded a 64.
Paul Dunne was towards the back of the field after a one-over 71.
Making his first start since threatening to claim a 15th major title in the Open at Carnoustie, Woods carded an opening 66 at Firestone Country Club, his lowest score in the first round of a PGA Tour event since August 2015.
Starting from the 10th, the 42-year-old picked up shots on the 11th and par-five 16th before ending the back nine in style, hacking his second shot out of the rough to the front edge of the green and then holing a curling putt from 50 feet for an unlikely birdie.
After missing just one fairway on the back nine, Woods missed three more in succession after making the turn, but scrambled for par on each occasion and then holed from 15 feet for birdie on the fifth.
Woods holed from 30 feet for another birdie on the seventh and then produced a brilliant recovery from the rough on the next, slicing his approach around a tree and on to the green.
The birdie putt pulled up inches short and Woods finally paid for some wayward driving when he was unable to scramble par on his final hole after finding a fairway bunker off the tee.
At four under par, Woods was three shots off the clubhouse lead held by fellow American Stanley, with Patrick Cantlay on six under and McIlroy part of a five-way tie on five under.
"Yeah, it was good," McIlroy told Sky Sports after a bogey-free 65. "I mean honestly we couldn't have got it easier this morning, no wind, very soft - you had to hit very poor shots to get it off line or to miss greens.
"Hopefully it firms up a little bit for the rest of the week but it was a day where you needed to take advantage of the conditions and I felt like I did that pretty well.
"I'm starting to drive the ball really well and there are a few tee shots out here if you can carry it over 300 yards it's a big advantage on the rest of the field.
"I just feel like this week is an ideal time to work on a few things [ahead of next week's US PGA Championship]. It's a great range, you get four rounds and sort of have a free run at trying things out.
"I felt I brought some of the stuff from the range onto the golf course and just have to work on it as the week goes on."