But in 62 rounds in this tournament dating to 1999, Woods made just a single birdie for only the third time.
And then he almost lost it.
His grandparents, Paul and Phyllis Thomas, watched him win for the first time on the PGA Tour.
The US PGA Championship - the final major of the year - begins on Thursday. "To make that putt on 1 and again on 2 just kind of calmed me and got me going for the day".
Woods, an eight-times champion at Firestone, dismissed speculation that his surgically-repaired back had bothered him.
"But I've put a few birdies on the board and I'm in position". McIlroy finished the front nine with consecutive bogeys and never recovered. He would make just one par on the back nine to go along with three birdies, three bogeys and two double-bogeys for a four-over 40.
Still, this is the first time since the 2015 Wyndham Championship that Woods has started a tournament with two rounds in the 60s, and it is the second-best he has been in any tournament this year through 36 holes; he was tied for second at the Valspar Championship.
The latter is certainly true, given his good form of late and his fondness for the course. "But it is what it is, and on to next week". We underrate how hard it is to present sufficient encores to elite seasons (which is what past year was), but Thomas has made it look fairly simple with maybe the most complete game on tour. That year, the WGC-American Express Championship (now the Mexico Championship) was scheduled for Bellerive but was canceled due to the September 11 terrorist attacks. He lost in the semifinals of the Match Play. This is one of the great classic golf courses.
So ended a finale at Firestone that otherwise lacked drama. "I've had a lot of really solid finishes, a lot of top-10s, or a lot of top-15s, but a lot of those have been because of a pretty good last day, as opposed to having a chance to win". But in if that's not enough to convince you that the man is a talented golfer, I present to you this bunker shot he made during the final round of the WGC-Bridgestone Invitational... The guys that I grew up playing against are going to be playing here next year (in a Champions Tour event). I loved playing here, even when it was the World Series of Golf. In many respects, it was the precursor to the World Golf Championships by bringing in winners from around the world.
The World Golf Championship will move to Memphis in 2019.
Thomas was far from his best as he played the opening 12 holes in level par and both Stanley and Jason Day eventually closed to within two shots, only to each promptly bogey the next two holes.
The 29-year-old mixed five birdies with two bogeys in a round that he admitted frustrated him as he struggled off the tee on the tight tree-lined fairways.
World number one Dustin Johnson and Dane Thorbjorn Olesen shot 64 and tied for third on 10 under.
Earlier this week, Rory McIlroy, who was paired with Thomas on Sunday, described his frequent practice partner as "nasty".