His five straight birdies quickly put him atop the leaderboard with Furyk, and after a 71-minute delay when storms moved into the area, Scott added a sixth birdie on the par-3 15th to reach 6 under. He was on pace to tie the major championship record at Oak Hill until a three-putt bogey on the 16th.
"Just got on a bit of a roll and hit a few shots close," Scott said. "I didn't have too much putting to do. You've got to take advantage when it happens, because it doesn't happen too much in the majors. Nothing to complain about in 65."
There were hardly any complaints on Oak Hill, a course that has yielded only 10 72-hole scores under par in five previous majors. It's only Thursday, and the players felt as if they got off easy. Rain overnight and humid conditions kept the course soft, and birdies were dropping at an alarming pace.
Except for Tiger Woods.
The world's No. 1 player made only two birdies despite playing in the still of the morning, and he watched his round fall apart with a bogey on par-5 fourth and a double bogey on his final hole when his flop shot out of a deep rough floated into a bunker. Woods had a 71 not a bad start at Oak Hill, except on this day.
There were 35 rounds under par, compared with only a dozen rounds in the 60s when the PGA Championship was here 10 years ago.
"The round realistically could have been under par easily," Woods said.
Furyk, who won his lone major at the U.S. Open in 2003 at Olympia Fields, has gone nearly three years since his last win at the Tour Championship to capture the FedEx Cup and win PGA Tour player of the year. Still fresh are the four close calls from a year ago, including the U.S. Open.
He was as steady as Scott, rarely putting himself in trouble until the end of the round. Furyk missed the fairway to the right and had to pitch out because of thick rough and trees blocking his way to the green. That led to his only bogey, but still his lowest first-round score in 19 appearances at the PGA Championship.
"Usually disappointed with ending the day on a bogey," Furyk said. "But you know, 65, PGA, is not so bad."
David Hearn of Canada, an alternate until a week ago, had a 66 in the morning. Also at 66 was Lee Westwood, who had his best score ever in the PGA and offered evidence that there was no hangover from losing a 54-hole lead in the British Open last month.
There were no record scores at Oak Hill despite the soft conditions, just a lot of low rounds.
"If you don't hit it in the fairways, then you won't score well," Westwood said. "These guys are good. There are a lot of good players playing in the tournament. Somebody is going to hit it straight, and somebody is going to shoot a good score."
Even Rory McIlroy got in on the act. The defending champion, at the end of a major season that has been a major disappointment, came out firing with three birdies on the opening four holes and made the turn in 32 until back-to-back bogeys.
Jim Furyk -5
Adam Scott -5
Rory McIlroy -1
Tiger Woods +1