No one felt that sense of suffocation more than Payne Stewart, who made several important putts but watched helplessly as a short one that missed by inches on the final hole rolled 20 feet away.
Chewing ferociously on his gum and wading almost constantly into the bogey-making rough, Stewart held on for a 71 to take a one-stroke lead over Jeff Maggert and Bob Tway at 3-under-par 137 after 36 holes.
Only Lee Janzen at two under par through 15 holes had a chance to catch Stewart among the several dozen players still on the course when he finished.
On a day in which Casey Martin and his cart and 19-year-old amateur Matt Kuchar made the cut for the weekend rounds, player after player succumbed to the unique demands of a U.S. Open golf course.
Nothing symbolized the frustrations of the day more than the 8-foot birdie putt Stewart had on the final hole.
The ball missed the cup by inches, nearly came to a stop, then gathered speed and rolled 20 feet past the hole while the knickered player stood helplessly with arms folded and watched.
"I really thought I would have about 3 or 4 feet coming back up the hill," Stewart said. "Then all of a sudden it's 20 feet."
He missed the putt coming back for his third bogey in five holes.
"That was borderline ridiculous where they had the pin," he said. "I wasn't really pleased about that."
Stewart's finish was reminiscent of the 1996 U.S. Open when he made bogeys on two of the final three holes to let a lead slip to one stroke. He ended up finishing 27th.
While others around him were unraveling _ including Tiger Woods, Colin Montgomerie and Fred Couples _ Stewart, who finished the first round with three consecutive birdies, started Friday with three more.
He then settled into doing what needs to be done to win a U.S. Open _ make a lot of putts to save par, including key ones on Nos. 11, 13 and 16.
But bogeys on Nos. 14, 17 and 18 let a lot of players back into the tournament. One of those was David Duval, who shot a 68 and was lurking at 143, suddenly only six strokes back going into the weekend.
Nine players started the second round under par, but that number dwindled as the day went on and the thick El Nino-fed rough swallowed up shots and the wind-dried greens grew faster by the minute.
Of those nine, only Maggert was able to improve on his score, shooting a 69 to be at 138 along with Tway. Kuchar and Lee Porter were at 139.
"The style of golf that we play at the U.S. Open suits my game very well," said Maggert, who was in a final-round duel with Montgomerie, Ernie Els and Tom Lehman last year at Congressional before finishing fourth.
"I took a lot away from that tournament," he said. "I am looking forward to getting myself in a position like that again and hopefully I can better my performance than what I did last year."
Maggert rebounded from bogeys three times on Friday and _ in perhaps the key to winning a U.S. Open _ managed to make bogey his worst score on any hole.
Woods was not as lucky. He had a second four-putt green in two days _ this one on No. 6 _ and made his fifth double bogey in his last six U.S. Open rounds. He shot a 72 and was at 146, nine strokes back.
Defending champion Ernie Els shot a 70 and was at 145.
Perhaps the most surprising player to hang tough _ and in fact gain on the field _ was Kuchar, who shot a 69 to get to 139.
"I'm definitely playing the weekend right?" Kuchar said. "I made my major goal. I wanted to be out here for Father's Day and my birthday," both of which are Sunday.
Sunday will be a special day for Kuchar, whose smile charmed the galleries at Augusta National in April when he finished 21st at the Masters, because his father, Peter, is also his caddie.
Joining Kuchar in making the cut for the weekend rounds was Martin, the 26-year-old Nike Tour player who successfully sued the PGA Tour to be allowed to ride a cart because of a circulatory problem in his right leg.
Martin shot a solid 71 in the second round and was at 5-over-par 145.
"From where I was eight or nine months ago" when his legal status was in doubt, "I am very lucky to be here," Martin said.
Stewart threatened to sprint away from the field when he started Friday with birdies on the first three holes to get to seven under par.
But Olympic is a course where you have to put strokes in the bank when you have the chance because withdrawals from that account can come at an alarming rate.
One of the best examples of how quickly things could go wrong was Justin Leonard.
Leonard had a 25-foot birdie putt on the par-3 15th hole to go to even par but had a four putt, missing twice from 3 feet, and then made consecutive bogeys to finish with a 75 for a 146.
Whoever wins this Open will certainly have to endure more of the same on the weekend.