O'Hern figured the match was over.
"I wasn't watching, to be honest with you" O'Hern said. "I was just waiting for the sound of ball going into hole."
Only after Woods struck his putt did he notice the ball mark he neglected to repair, which he said caused the ball to bump slightly off line to the right and slide by the cup. One hole later, O'Hern made a 12-foot par putt that sent Woods home without a trophy on the PGA Tour for the first in more than seven months.
Woods is such a master of the minutiae that when he arrived Monday afternoon at The Gallery, he fretted over a new putter grip being off by the tiniest fraction. Four days later, he failed to fix a ball mark that cost him dearly.
"I was so enthralled with the line, I didn't see the ball mark," Woods said. "I knew if I hit it left-center, the match would be over. It's my fault for not paying attention to detail."
So ended the second-longest winning streak on the PGA Tour, returning Byron Nelson's record of 11 straight PGA Tour victories to "untouchable" status and making Woods start over next month at Bay Hill.
The streak was always subject to debate. Some thought it should carry an asterisk, for his winning streak ended at five when he lost in the first round of the World Match Play Championship on the European tour last September, and Woods had since failed to win three other times outside the PGA Tour.
It was this fickle format that stopped him again.
And it was a familiar foe.
O'Hern became the first player to beat Woods twice in match play as a professional. The short-hitting lefty from Australian also beat him in the second round two years at La Costa, and in both matches, O'Hern never trailed a single hole.
"To beat him once was an amazing thrill," O'Hern said. "I'm sure he wanted to even the score today. I just knew if I played well and played solidly, I could do it again."
But he needed some help, and Woods obliged early and late.
Woods was so errant on the front nine that he had to pluck cactus spines from the seat of his pants after one too many trips into the desert, giving him two double bogeys as O'Hern built a 4-up lead through seven holes. Woods rallied to square the match on the 15th, again on the 18th, and was ready to claim victory with that 4-foot birdie putt on the 19th hole.
"He let me off the hook," O'Hern said.
It is rare that Woods makes such a gaffe. It certainly was a shocker to O'Hern, especially after he watched Woods rip a 342-yard drive and hit sand wedge into 5 feet for birdie on the 18th hole that sent their third-round match into overtime.
Woods was just short of the par-5 first hole in two and ran his chip 4 feet by. O'Hern missed from 25 feet and picked up for par, then waited to remove his cap and shake hands with Woods.
"My caddie gave me another ball and said, 'OK, next hole,'" O'Hern said. "I said, 'Mate, he doesn't miss these.'"
He missed this one.
On the 20th hole, Woods was in the middle of the fairway and pulled his 4-iron into a stiff, cool breeze left of the green. He said the greens had been cut again _ the tour said that wasn't the case _ and left his chip 15 feet short, missing the par putt. O'Hern hit out to 12 feet from the bunker, and his winning putt curled in the right side.
It was longest match Woods had played in this tournament, except for the 36-hole finals he reached three times.
And it was the end of a winning streak that began at the British Open with an outpouring of ters and ended in the high desert north of Tucson with an outpouring of disgust.
"It's not the streak," Woods said. "It's the fact that I'm disappointed I didn't pay attention to detail, something so simple. Something so simple like that just escaped me."
The only people who felt worse than Woods were tournament officials who longer have the No. 1 draw.
Henrik Stenson (No. 9) is the top seed remaining going into the weekend, a 4-and-3 winner over Aaron Baddeley that will put the Swede into the quarterfinals against O'Hern.
In other matches:
_Chad Campbell was the lone American left at The Gallery, advancing to the quarterfinals for the second straight year with a 1-up victory over David Toms. Campbell will play Stephen Ames, a 3-and-1 winner over Stewart Cink.
_Paul Casey beat Shaun Micheel for the second time in five months, 2-up. Casey also beat the former PGA champion in the final of the HSBC World Match Play Championship in September. He will face defending champion Geoff Ogilvy, whose 2-and-1 victory over Niclas Fasth gave him his ninth straight match victory.
_Justin Rose built a big lead and beat good friend Charles Howell III, 3 and 2. Rose will play Trevor Immelman, who won 2-and-1 over Ian Poulter in a tight match where 13 of the 17 holes were halved.
Immelman was the last player to win a PGA Tour event that Woods played, at the Western Open last July.
Woods hardly looked like a player who has streaking toward Nelson's record, missing a 4-foot par putt on the third hole that would have given him the lead, then spraying tee shots into water and desert sand.
His tee shot flared into the wind and dropped into the water on his way to double bogey on the fourth hole. He hit another drive on No. 6 that landed at the base of a saguaro cactus, and he took two shots to move the ball 35 feet out of the desert in taking another double bogey. On the seventh, Woods' drive landed at the base of a desert shrub, and he blasted that over the green to fall four holes down.
"It was a struggle," Woods said. "I just didn't have control of my golf swing. I had a two-way miss going today."
But he pecked away at the lead, building momentum along the way with birdies on the eighth, 11th and 12th holes and finally squaring the match on the 15th when O'Hern took two chips to reach the green.
Woods didn't put much thought into the streak, but looked back on it with pride.
"To go basically from July until now without ever finishing out of the top three, that's not bad," he said.