It was an opportunity lost for Woods, who began the day tied for the lead with Rory McIlroy but dropped back to a tie for 12th, five shots back of Xander Schauffele, after bogeying the final two holes.
Woods said much of Thursday's success was down to him dusting off the 19-year-old putter he used for 13 of his 14 major wins.
Woods was joined in the lead by McIlroy who highlighted his round of 10 birdies with a career-best six in succession, beginning with the last hole of his front nine.
Schauffele shot 67 to take a share of second a 16 under with four-time major victor Rory McIlroy (63).
One day after a 62, Woods shot 70 and was five behind.
A 20-foot birdie at his first hole, the 10th, was a confidence-boosting start in oppressive humidity on the Aronimink course in the rolling hills just west of Philadelphia. Surprisingly, Schauffele now has a 2-stroke advantage over his nearest competitor Justin Rose. He shot 1-over 71 and fell to 32 in the FedEx Cup standings, so he needs to put a move together quickly in order to avoid missing out on the Tour Championship.
The current world No 8 sounds excited and there's enthusiasm not only in his eyes but in his manners and his speech in a rain-affected BMW Championship.
"I have to make birdies and try and keep pace", Woods said. I hit it to three feet on the fifth hole and missed it and I finally got one to go on six and felt like I at least got something going. It looked like all the putts were going to go in, but they didn't go in today.
At stake for Rose is moving to No. 1 in the world for the first time in his career.
"I know I'm capable of low scores but the calibre of players on this BMW leaderboard is so high", he said. If Schauffele wins this week, it'll be very hard not to send him to Paris.
Jason Day (64) and Justin Thomas (67) are level with McIlroy on nine under, while Tony Finau matched Schauffele's score to get to eight-under.
Ian Poulter's chances of a Ryder Cup pick took a slight knock after missing the cut and falling seven spots into 45.