Andrew Landry retained a share of the lead at the U.S. Open, despite taking only one stroke on Friday at Oakmont Country Club. He made birdie to conclude a first-round of four-under par 66.
Dustin Johnson, meanwhile, posted a one-under par 69 in the second round to tie the lead, though Landry still has to play the second round on Saturday morning. Johnson, sixth in the World Ranking, is in pursuit of his first major championship. Lee Westwood shot a 67 in the first round and is in third, a stroke back.
Landry and the 77 other players originally scheduled to play on Friday afternoon, will play their second round on Saturday morning, in addition to the 39 afternoon-wave players unable to finish on Friday night because of darkness.
"I mean, being on top of the leaderboard is fine," said Landry. "It's just there's so much golf left, and there's people who can blow it up and say, 'You're doing great.' Yes, I am doing great, but there's 54 more holes left."
Johnson played 36 holes on Friday and shot 67-69 to ascend to a tie with Landry.
World No. 1 Jason Day, who struggled to a six-over 76 in the first round, was one under over 15 holes in the second round.
Phil Mickelson was three over through 15 holes in his second round, putting him at seven over and at risk for missing the cut.
Sergio Garcia, Scott Piercy and Shane Lowry are all tied at two under, just two strokes back of the lead.
Notable players who will start their second round in the morning include Landry, Bryson DeChambeau (one over), Jordan Spieth (two over), Danny Willett (five over), Rickie Fowler (six over) and Rory McIlroy (seven over).