FARMINGDALE, N.Y. — Halfway through his third round, Ricky Barnes had a six-shot lead and a smile to match in the U.S. Open. Ten holes later, with darkness gathering, he couldn't get off Bethpage Black fast enough.

The final few hours yesterday changed everything in a start-and-stop U.S. Open headed for a Monday finish.

Barnes became only the fourth player to reach double digits under par, but had to settle for an even-par 70 and a one-shot lead over Lucas Glover after the rain-delayed third round.

In the one hole he completed in the fourth round, Barnes chopped his way to a bogey and fell into a tie. He followed that by hooking his tee shot into gnarly clumps of native grass on a hill left of the second fairway, putting him in more trouble.

When the horn sounded to suspend the final round because of darkness, he quickly marked his ball and headed for the clubhouse.

Barnes and Glover were at 7 under par, still five shots clear of everyone else.

Neither of them has ever faced the pressure that comes with contending in a major championship — Glover had never even made the cut in a U.S. Open before — and they still had a long way to go.

"It's going to be pressure-packed tomorrow," Glover said. "I'll sleep fine. If not, I guess I'll be tired."

Phil Mickelson, determined to bring a fairy-tale finish to a U.S. Open career filled with disappointment, made seven birdies in his third round of 69 that left him six shots behind. 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.

He played two holes, narrowly missing birdie putts on both, and was five shots behind at 2 under.

David Duval, another unlikely contender having slipped to No. 882 in the world ranking, also was in the group at 2 under that included Hunter Mahan and Ross Fisher of England.

Tiger Woods at least left Bethpage Black in good spirits.

Having squandered so many birdie chances over the past two days, Woods made an 8-foot birdie on the 489-yard seventh hole to get back to even par for the tournament for the first time since his 14th hole in the opening round. Woods was 15 shots behind at one point Saturday, but he walked off the course seven shots back with 11 holes to play.

"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 today to resume the final round at 3 a.m. Hawai'i time, 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 2 1/2 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 4-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 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.

The largest final-round U.S. Open comeback is seven shots in 1960.

"Anything can happen in a U.S. Open," Mickelson said.