Jim Furyk fired his lowest opening round in his 73 major appearances as he set a testing early clubhouse target at the US PGA Championship.
The 43-year-old shrugged off a closing bogey as he reflected on a superb six-birdie 65 that earned him the outright lead on five under par.
The American veteran started with a morale-boosting birdie at the 10th, and he picked up further shots at the 16th, 18th and first holes in a sparkling mid-round charge.
He added further birdies at four and seven before blotting his card with a five at the tough ninth, and he said: "You're usually disappointed to end the day with a bogey, but a 65 at the PGA, that's not so bad.
"I had a good ball-striking day. I felt like the golf course would be a good fit for me. It's set up a lot like a US Open course.
"I missed one drive in the heavy stuff but overall a good day. It was good to get my feet under me. I got relaxed and settled into my game. I got on a roll and got a lot of confidence out there.
"You don't win the golf tournament on Thursday. I know that. I'm just happy with playing well and putting myself in a good position."
Furyk has not won since the Tour Championship three years ago, and he admitted erratic form with both his putter and driver had caused him problems.
"I did not feel confident with my putter and that was putting a lot of pressure on the rest of my game," Furyk added.
"I worked real hard the last two weeks on fixing those problems and feel very comfortable with what I'm doing with my driver right now.
"I've been doing some work on the putting as well and today was probably one of the best puttings rounds, if not the best, I've had this year.
"I did a good job of getting the ball on a good line where I was looking and I was able to manage where I wanted the ball to go."