Fresh from back-to-back wins on the PGA Tour in the last two weeks, the world number one delivered a superb display from tee to green on the monster Hazeltine National course.
Woods, in pursuit of his 15th major victory but first this year, birdied three of his last eight holes to finish a stroke in front of playing partner and defending champion Padraig Harrington.
Twice champion Vijay Singh of Fiji, 2001 winner David Toms and fellow American Hunter Mahan, Australians Robert Allenby and Mathew Goggin and big-hitting Spaniard Alvaro Quiros were all on 69.
Britain's Lee Westwood, who finished one stroke out of a playoff for last month's British Open won by American Stewart Cink, was among a group of eight on 70.
Although the 7,674-yard layout is the longest to stage a major, Woods and company took advantage of its generous fairways and softened greens in hot, humid conditions.
"The way the course is set up you can be a bit aggressive," Woods told reporters after recording his lowest opening round at the PGA Championship since firing a 66 at Valhalla in 2000.
"I played really well today and felt very comfortable with what I was doing. It's always nice to get off quick. In the first round you can play yourself out of a golf tournament but you certainly can't win the tournament on the first day.
"I hit a bunch of good shots and this round could have been really low," he added after reaching 15 of 18 greens in regulation. "I missed a bunch of putts out there."
Woods, champion in 1999, 2000, 2006 and 2007, totalled 29 putts including three from 20 feet or more.
Allenby echoed the thoughts of many in the 156-strong field about the American's blemish-free performance.
WORLD'S BEST
"Obviously he's the best in the world so we expect him to win," the Australian said after recording five birdies and a double-bogey seven at the 15th after finding a plugged lie in a fairway bunker off the tee.
"But you know what, it's three more days to go and a lot can happen. There are a lot of good golfers behind him."
Irishman Harrington, who clinched last year's title by two shots at Oakland Hills, relished his high-profile grouping with Woods in front of huge galleries.
"It puts you under a bit more pressure," the three-times major winner said after hitting five birdies and a lone bogey at the par-four first. "You have to go to a new level. It pushes you on and that's what I like."
Harrington is bidding for his first victory on either the PGA or European tours this season after working hard on refining his downswing over the last eight months.
Singh, champion at Sahalee in 1998 and Whistling Straits in 2004, was among the best of the afternoon starters and soared up the leaderboard with five birdies and two bogeys.
"I drove it really well ... and the putting was good," the former world number one said after picking up two shots in his last three holes.
Several big names, however, failed to take advantage. American Phil Mickelson, the 2005 champion at Baltusrol, opened with a 74, US Masters champion Angel Cabrera of Argentina carded a 76 and Australian Adam Scott slumped to an 82.