Instead, the Irishman had an even worse collapse Sunday at Hazeltine National Golf Club.
Harrington put two shots into the water and had his playing partner ducking out of the way of a third en route to a quintuple-bogey 8 on the par-3 eighth hole that transformed him from Woods' biggest threat to a punch line in a matter of minutes.
The disaster dropped Harrington from 6 under to 1 under, and he limped to a 78. He finished even par for the tournament, eight strokes behind Y.E. Yang, who became the first player to rally on the final day of a major to defeat Woods.
Harrington had stayed with Woods all week, and he was just one stroke behind him when he went to the tee on the 167-yard eighth. But he couldn't get his tee shot over the water and then, after taking a drop, nearly hit Stenson, who was standing just above the bunker to the left of the green.
"It was a difficult tee shot and it was obviously a difficult second shot after you hit it in the water and pulled it left," Harrington said. "I had been changing my chipping action a little, and I probably was more into what I was doing rather than trying to get the ball up-and-down, and you know, I hit a bad shot. So these things happen."
Things only got uglier.
He put far too much oomph on his fourth shot near the bunker, and it sailed over the green and into the water.
After his second drop of the hole, a skittish Harrington was far too soft with his chip from the rough, and the ball only traveled a few feet. Mercifully, Harrington dropped a 5-foot putt for his 8.
He walked off the green to sympathy applause from the crowd and with a smile on his face, trying to make the best of an embarrassing collapse.
"It's hard when you are messing up like that," Harrington said. "I holed a lovely 5-footer down the hill there and made a great up-and-down from a bad lie. I finished the hole off strong and can't ask for anymore than that."
The performance came just a week after a similar blunder at Firestone. Locked in a duel with Woods for the title, Harrington had a triple-bogey on the 16th hole, including a chip over the green into the water, to wilt out of contention.
Woods defended his friend after the Bridgestone, criticizing tour officials for putting the pair on the clock earlier in the round. Harrington said he felt rushed after the warning, but he had all the time in the world Sunday.
"Paddy is an extremely hard worker, very patient and really believes in his game," Woods said Saturday. "It's really nice to see someone who works that hard at his game to accomplish his goals, and that's certainly one of the things I've always admired about him."
Harrington's goal Sunday was to earn his fourth major title. No rival of Woods has won more than three majors since the world's most dominant golfer joined the PGA Tour in 1996.
Harrington parred the first seven holes Sunday, looking every bit the steady, unflappable competitor Woods has lauded him to be.
It was on No. 8 where he decided to try to make a move.
Instead of playing his tee shot safer and sending it toward the left side of the green, Harrington tried to go over the water on the right side.
"In fairness, when I was on eight, I didn't feel like I could afford to make bogey by hitting left like most people," Harrington said. "I decided I've got to hit the shot. ... It wasn't a day that I could give up a shot by hitting in the left-hand traps, and such is life.
"Some days they don't come off, some days they do."