FARMINGDALE, N.Y. -- Ricky Barnes flashed a smile as big as his six-shot lead.
He was double digits under par, only the fourth player in U.S. Open history to get that low. He had a six-shot lead over his closest rival, while the stars struggled to make up ground. Phil Mickelson was making as many bogeys as birdies. Tiger Woods fell 15 shots behind.
It all changed in a New York minute.
When darkness settled over Bethpage Black as the final round was still young, Barnes was tied for the lead with Lucas Glover. Both of them were at 7-under par, five shots clear of anyone else. Neither has ever faced the nerves of contending in a major.
What once appeared to be a two-man race suddenly had endless possibilities:
• Mickelson made two long birdie putts on his last three holes for a 69 in the third round, and after pars on the two holes he played in the final round, he was only five shots behind.
• David Duval, a former British Open champion without a victory in eight years, kept coming back from sluggish starts and found himself very much in the hunt at 2 under with 16 holes to play.
• Woods finished a frustrating day on the greens with an eight-foot birdie putt on the 489-yard seventh hole, putting him at even par in the tournament for the first time since the 14th hole of the opening round. He was seven shots behind with 11 to play.
Barnes, who finished the third round of this rain-delayed U.S. Open with a one-shot lead at 8-under 202, chopped his way to bogey on the opening hole of the final round to lose his lead. Then he hooked his tee shot into gnarly clumps of the grass along a hillside left of the fairway on No. 2.
When the horn sounded to stop play, he quickly marked his position and walked briskly off the course.
"It's going to be pressure-packed tomorrow," Glover said. "I'll sleep fine. If not, I guess I'll be tired."
Mickelson, determined to bring a fairy-tale finish to a U.S. Open career filled with disappointment, was on the third tee and had plenty of golf left. He has been the runner-up four times in the U.S. Open -- three times in New York -- and is desperate to bring a silver trophy of cheer home to a wife who is battling breast cancer.
"I'm one good round away," Mickelson said, excited at the possibilities.
Hunter Mahan and Ross Fisher of England were also at 2 under. Former Masters champion Mike Weir was at 1 under.
Woods at least left Bethpage Black in good spirits.
"It was nice to end the day with a birdie on one of the most difficult holes of the week," Woods said.
The USGA felt good enough about the forecast Monday to resume the final round at 9 a.m., leaving enough time for an 18-hole playoff if it comes to that.
It will be the first time a U.S. Open ended in regulation on Monday since Larry Nelson won at Oakmont in 1983.
And if the 2½ hours of golf played in the final round were any indication, it could be as much about survival as a big charge. The third round ended with 11 players under par. When play was suspended, only seven remained.
Barnes looked as though he might blow this major wide open after rolling in a 25-foot eagle putt on No. 4 in the third round to reach 11 under, joining Gil Morgan (1992), Woods (2000) and Jim Furyk (2003) as the only players to reach double digits under par in a U.S. Open. When he reached the 10th tee, he was six shots clear of Glover.
What looked like a breeze turned into a struggle, however.
Barnes hit only three fairways on the back nine, and after steadying himself with a 35-foot birdie putt on the 17th, he failed to save par on the 18th by missing a four-foot putt that never touched the hole. He wound up with a 70 to finish 54 holes at 8-under 202.
Glover rallied behind flawless golf that included three birdies and a 32 on the back nine and also shot 70 to stay one behind.
"I knew it was going to be wet and tough, and I knew my nerves would be tested," Barnes said. "I wouldn't have liked to bogey the last hole and end it that way. But I've got to go back, take my shoes off and think, 'Hey, I shot even par on Saturday with the lead.' If I go out and do the same thing, someone is going to have to really come back low ... to catch me."
The finish might be as unpredictable as the weather that has otherwise made a mess of this U.S. Open.
Mickelson could be the one player to make the misery of slogging through the mud over five days easy to forget. He already is a crowd favorite in New York, and the affection for him has become even more tangible since disclosing that his wife, Amy, has breast cancer.
Lefty made his share of mistakes, as always, but he countered with seven birdies in the third round to give himself a chance. Not even a six-shot deficit bothered him.
"I feel like if I can get a hot round going, I can make up the difference," he said.
For the second straight round, Duval was on the verge of falling away until he picked himself back up. Right when he was about to fall back to par, Duval hit a shot out of trampled rough and around a tree to 10 feet for birdie on the 16th, and he hit a 7-iron to 7 feet on the final hole for another birdie and a 70.
He again started sluggishly in the final round, taking bogey from the rough on No. 1 and having to save par from thick grass short of the green at No. 2. Duval has not won in eight years, and he has not finished in the top 10 since 2002.
Woods made only one mistake in the third round -- taking two hacks with the wedge to escape knee-high grass around the 14th green -- but more troubling was that he made only three birdies after giving himself so many chances inside 15 feet. He had to settle for a 68 and was nine shots behind. He has never won a tournament trailing by more than eight going into the final round.
"Obviously, it's not totally in my control," Woods said. "Only thing I can control is whether I can play a good one or not."
Most players had a hard time remembering what day it was in this on-again, off-again Open in which no round has been completed on the day it started. There was another 4½-hour delay Sunday morning because of nearly an inch of rain overnight.
Mickelson has a tropical vacation planned with his wife and their three children before her July 1 surgery for breast cancer, although he was in no hurry to get home now. He has been runner-up four times in this major -- already tied for the record -- and talked earlier this week about Amy leaving him messages to bring home the trophy.
The largest final-round U.S. Open comeback is seven shots in 1960. Mickelson was one closer than that, and he could practically taste it.
"Anything can happen in a U.S. Open," he said.