Oakmont, Pa. It was a simple shot on a difficult golf course, a 135-yard sand wedge from Angel Cabrera that skidded to a stop a foot from the hole, a rare birdie at Oakmont that changed so many things.
It put Cabrera atop the leaderboard as the sole survivor to par Friday at the U.S. Open.
And it sent Phil Mickelson home early from a major for the first time in eight years.
"I did not knock out Mickelson," Cabrera said. "Mickelson knocked himself out. He shot 11 over par."
But whether it was the 37-year-old Argentine holding a one-shot lead, Paul Casey with a score 11 shots better than the field or Tiger Woods salvaging his hopes out of Church Pew bunkers and devilish rough, there was one consensus.
Oakmont figures to pack the biggest knockout punch of all.
Cabrera's birdie on his final hole gave him a 1-over 71 and a one-shot lead over Bubba Watson. It also ended this U.S. Open for Mickelson and 18 other players who no longer were within 10 shots of the lead.
Considering what the weekend holds, maybe Cabrera did them all a favor.
"If you're a 10-handicapper, there is no way you're breaking 100 out there," Woods said, presumably speaking more to fans watching this horror show than the 35 players who couldn't break 80 on Friday.
Cabrera was at even-par 140, the first time since the 1974 U.S. Open at Winged Foot that no one was under par after 36 holes.
"It's a real test of golf, all the way through," Watson said after a 71. "Just walking through the parking lot is tough."
Mickelson found it tougher than ever. The guy with a broken heart from his collapse last year at Winged Foot was no match with a gimp wrist at Oakmont. He slashed out of the rough and chased putts around the hole, leading to a 77 that caused him to miss the cut for the first time in 31 majors, since the 1999 British Open at Carnoustie.
He headed back to his room to "watch the carnage on TV."
And that's what it was.
Greens that had been cut three times and rolled twice, combined with warm sunshine that cooked the course, led to only two rounds under par and the highest weekday scoring in 21 years.
"I don't know what the average score was, but I think I shot under par," Woods said after a 74 that put him five shots back.
Even more shocking than the toughness of Oakmont was seeing Casey with a 66, a round so superb that players on the practice green who watched him finish on No. 9 applauded when he knocked in his final putt.
The average score Friday was 76.933, the highest before a cut at the U.S. Open since it was 77.8 in the wind-blown first round at Shinnecock Hills in 1986.
"I consider the U.S. Open to be the toughest test in golf," Casey said. "This is possibly the toughest golf course I've ever played, and I feel very, very lucky to have shot 66 on it. There is no rest out there."
And there might not be any relief in sight.
The USGA said it would water the greens overnight, but with more sunshine in the forecast, Oakmont figures to get even more brutal.
Stephen Ames had the other subpar round (69), leaving him at 142 along with Aaron Baddeley (70), Justin Rose (71) and Niclas Fasth (71). Casey was at 143, with David Toms in the group another shot behind.
The USGA, as usual, offered no apologies.
"It's a hard golf course. We've said that all along," said Jim Hyler, head of the championship committee for the USGA.
Mickelson wasn't the only one checking out. Five of the top 10 players in the world ranking failed to make the cut, the others being Adam Scott, Henrik Stenson, Luke Donald and Retief Goosen.
Trevor Immelman leaned against a wall in the locker room after a 79 that eventually sent him home. He stared blankly at the television, watching other players suffer, trying to come to grips with how Casey posted five birdies and only one bogey.
"The greatest round I've ever seen in my life," said Immelman, who played with the Englishman. "He beat me by 13 shots. That's almost giving him one shot per hole."
Casey didn't exactly have his way with Oakmont. He birdied the two toughest holes in the second round, including a 45-foot putt on the treacherous 10th green. And he saved a couple of pars with putts that felt as though they would slide off the green if the hole didn't happen to get in the way.
"I know the scores are quite high today and I shot a low number," Casey said. "But I don't think we've seen half of Oakmont yet."
The only other time Cabrera has had the lead in a major was three years ago after the first round at Shinnecock Hills. Watson, the biggest hitter on the PGA Tour who is using several irons to keep the ball in play, is playing in his first U.S. Open and hasn't won anything since the Hooters Tour four years ago.
Along with a challenging course, they now must cope with the nerves of playing in the last group on the weekend at a major.
"I'm always nervous," Watson said. "The U.S. Open is going to be bigger crowds, and I'm going to be just as nervous and feel like throwing up the whole time."
Indeed, it was a sick feeling for everyone.
Defending champion Geoff Ogilvy shot a 75 and was still in the game at 146, but it sure didn't feel like it.
"You're satisfied when you look back on it and see that you did it better than anybody else," he said. "But fun? No."
David Toms had a share of the lead for the second straight day, but like so many other players, Oakmont eventually got the best of him. He bogeyed five of his last six holes Thursday, and played his last five holes Friday in 4 over par.
Even so, he was at 144, along with Scott Verplank (71) and Brandt Snedeker (73).
"They teased us yesterday with some of the easy pin positions, and today when you woke up, they let you know we're at Oakmont," Snedeker said. "It's just going to be a tough round of golf."
Woods figured that out when he started to hit his tee shots into the ankle-deep rough, and it really hit home when his approach landed on the front part of the first green and never had a chance to go anywhere but into the rough.
"Thank God I had spikes on, because I think I would have slipped right off the back," he said.
His ugliest hole saved his round - an iron he pulled into the rough, a second shot that caromed off the bank and into the bottom of a shallow ditch, a third shot into a bunker on the other side of the green, and an up-and-down for bogey.
It is days like this that make players wonder whether the U.S. Open is any fun or the course is fair.
"It's a mean course," Jim Furyk said after a 75 put him at 6-over 146. "Rarely do you hit a marginal shot and get away with it. And oftentimes, you hit a pretty darn good shot and it doesn't turn out well."