Woods has gone 14 years since he last won the green jacket, 11 years since his last major and had five surgeries - four on his back, the other to rebuild his left knee.
Francisco Molinari, Jason Day, Brooks Koepka, Adam Scott and Louis Oosthuizen all share the lead at seven under. Dustin Johnson, the 20-time TOUR victor who captured his first and only major at the 2016 U.S. Open, shot 70 and was also 6 under.
"I think just an understanding of how to play and handle the bigger tournaments, and understanding how to deal with pressure a little bit better, " Koepka said of his recent run of three majors in his last six tries.
But he missed a 5-footer for par at the fifth; three-putted the eighth to bogey a par-5; had it to 5 feet after an excellent approach at the par-3 12th and failed to convert.
Koepka, a victor in two of the past three majors, ran off four straight birdies in the middle of the back nine by overpowering a soft course. It added up to a 68 for the Australian who won the Masters six years ago, and has gone three years since his last victory.
Woods' birdie at the 11th - the only one there all day - seemed to spark him, as he then hit his tee shot stiff at the 12th, only to have the horn blow stopping play due to a unsafe weather situation.More news: Dave Joerger becomes victim of Vlade Divac's Kings power grab
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"It is really an incredible leaderboard", Scott said. He missed previous year recovering from a wrist injury that left him wondering if he would ever play again.
Woods, 43, still got on the leaderboard despite playing the par-5s in even par. "To be where I'm at, as badly as I putted and hit the ball today, I'm pleased with it".
Woods leapt into the air to avoid injury and though the security guard seemed to clip his right foot, he appeared to come away unscathed, despite briefly grimacing as he made his way back to the fairway.
As a gentle rain fell, Woods hit a low hook around the trees on the 14th hole and onto the green.
"You're going to be tested in a major championship one way or another", Koepka said. Bryson DeChambeau, who shared the 18-hole lead with Koepka, went bogey-double bogey around the turn and shot 75.
He knocked in the eagle putt to move to eight-under par.