OAKMONT (AFP) - The US Open was left finely poised late Saturday when fading light forced third-round play to be called off with Ireland's Shane Lowry leading a chasing pack all primed to pounce.
A total of 32 players out of the 67 who made the cut were unable to finish their rounds before nightfall.
They will head back out at 7am Sunday morning (7am, Monday, Singapore time) to finish up and then have a break before the final 18 holes get underway.
The clubhouse lead was held by South Africa's Branden Grace, who had a four-under 66 for a total of one under par.
That was two shots better than world No. 1 Jason Day, who clawed his way back into contention on the back of a 66 and young American Bryson DeChambeau, who had a 70.
"I stayed patient, I took my chances when they came my way and I actually hit the ball 15 out of 18 greens. Gave myself plenty of chances. I missed a few, but I made up for a few of the long ones," Grace said.
Day said that "physically and mentally" it could be tougher on those players who would have to get up at the crack of dawn to finish their rounds.
"I think I have given myself an opportunity of getting there," said the Australian, who won his first Major at last year's PGA Championship.
Out on the course when the horn was sounded to end play, it was the bearded Lowry who was best placed, standing at five under and leading the field by two with four holes left to play.
"This is exactly where you want to be. I've been beating myself up over the last six months trying to get in this position. I'm here now. I might as well enjoy it while I'm here," he said.
Next best was American Andrew Landry, the first-round leader who again belied his world ranking of 624 to stand at three under after 13 holes.
"I think I did a really good job out there. No nerves, very comfortable," said Landry of his afternoon's play in what was for him elevated circumstances.
English veteran Lee Westwood, Spain's Sergio Garcia and halfway-stage leader Dustin Johnson were all on two under, each with a handful of holes to play.
It was a dramatic day of rapidly fluctuating fortunes which started with Johnson ahead by one only for three others - Westwood, Landry and finally Lowry - to take the outright lead in turn.
The famed Oakmont course, soaked and softened by torrential rain during Thursday's opening round, turned fiery and fierce under a hot sun and matching par became the order of the day.
Only six players were left in red figures by the end of the day.
The big shock early on was that four-time Major winner Rory McIlroy failed to make the cut for the first time at a Major in three years.
The 2011 US Open champion went out in 31 and looked poised for a charge, but he inexplicably fell apart on his back nine, a 40 giving him a 71 and at eight over, he was on his way home.
Other notable casualties of the cut were six-time runner-up Phil Mickelson, who saw his dream of clinching a career sweep of all four Majors once again shattered, 2013 champion Justin Rose and an out-of-form Rickie Fowler who ended at 11 over.
Defending champion Jordan Spieth did make it through, but, after a hot start, he went off the boil and finished at four over, leaving him with a mountain to climb to defend his crown.
"Got off to a dream start for moving day, and then just kind of boned a wedge, kind of put a bad swing on a pretty stock shot that killed momentum. I went double-bogey, bogey," he said.