Shane Lowry will head into the final day at Oakmont Country Club with a two shot lead, having yet to complete his third round.
Saturday was busy and many golfers had to finish their second rounds before swiftly moving on to their third. The cut fell at six-over-par.
Eventually darkness curtailed the proceedings with Lowry leading on a five-under-par total.
At the start of the third round it was Dustin Johnson in front on four-under-par, one shot clear of rank outsider Andrew Landry, while Lowry was a further shot back on two-under-par.
The Oakmont greens got tougher as the day wore on and players struggled to keep a clean scorecard.
Landry and Lee Westwood had spells at the top of the leaderboard, but it was Lowry who claimed the initiative before play was suspended. The Irishman had an eventful front nine, sinking four birdies while bogeying the second and eighth to go out in 33 strokes (two-under-par).
This propelled him to the top of the leaderboard alongside Landry until the latter dropped a shot at the ninth.
Lowry sunk a crucial birdie on the par-five 12th for a two-shot buffer.
A few holes later and the players were called in because of the fading light, with the three-time European Tour winner still having four holes left to complete his third round. The final three-ball on the course of Johnson, Landry and Scott Piercy had completed 13 holes when play was halted.
‘We all know that this course can jump up and bite you in a split second,’said Lowry. ‘I’m two ahead with 22 holes left. These are the best golfers in the world behind me, Dustin (Johnson) and Jason (Day). Sergio (Garcia) played lovely today. I have to go out and do what I’ve been doing all week. I’m really looking forward to tomorrow.’
‘This is exactly where you want to be,’ the 29-year-old added. ‘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.’
World number one Day was able to finish his third round, firing a four-under-par 66 to sit in a tie for eighth alongside three other golfers on one-over-par.
Branden Grace is in with a shout after also shooting a 66 to be in sixth place on his own at one-under-par, four shots behind the lead of Lowry. It will be an exciting final day to see who will be crowned US Open champion for 2016.