OAKMONT, Pa. -- While the course was drying out, Dustin Johnson was heating up.
Overnight rainfall made for soggy conditions at Oakmont Country Club on Friday, but as the weather warmed up, the notoriously difficult course started playing truer to form.
For most, that is -- not Johnson, who seemed to play his best golf as the day progressed.
As it turns out, he was prepared for the situation.
"Fortunately, I came and played last Tuesday, the week before, and it had rained really hard Monday night, so I got to play it with it really soft," Johnson said after shooting a second-round 1-under-par 69 to move into a tie for first place at 4-under with Andrew Landry at the 116th U.S. Open.
Johnson nearly played another bogey-free round after firing a weather-delayed opening-round 67 on Friday morning following Thursday evening's rainout.
The world's sixth-ranked player bogeyed No. 1 -- his 10th hole of the round -- to snap a streak of 27 consecutive holes in the tournament without a bogey. He rolled in a pair of birdies Friday.
"It was a long day today, but I felt like I played really solid for all 36 holes," Johnson said. "I drove it really well. Hit a lot of great iron shots. Felt like I rolled the putter really nicely too. So very pleased with how it went today."
Johnson has six top-five finishes in his last nine events dating back to Feb. 21. He placed third at the Memorial Tournament in Dublin, Ohio, on June 5 and fifth at last week's St. Jude Classic in Memphis.
Landry completed his opening-round 66 on Friday morning after play was suspended due to heavy rainfall. His score was the lowest first-round mark in a U.S. Open at Oakmont, and he will tee off his second round at 7:11 a.m. on Saturday.
"I think the U.S. Open just suits my game so well that I'm just able to manage these things," Landry said, "because I'm not a guy that's going to go out and shoot 60 and 61 and 62.
"I'm just a consistent guy that's going to shoot 68 and make a lot of pars."
Play was suspended at 8:48 p.m. Friday due to darkness. Second-round play resumes Saturday morning at 7 a.m., with 61 players yet to complete their round.
Lee Westwood of England has sole possession of third place at 3-under and begins his second round Saturday at 8:28 a.m. Scott Piercy, Sergio Garcia of Spain and Shane Lowry of Ireland are in a three-way tie for fourth at 2-under.
"It is really tough the way it's playing right now, being a little bit softer," Garcia said of the par 70, 7,219-yard course.
Piercy, who briefly grabbed a share of the lead at 4-under in his first round Friday morning, canceled out his five birdies with five bogeys to shoot an even-par 70.
"Putter let me down a little bit in the afternoon, but the ball striking was really pretty amazing in the afternoon for sure," Piercy said.
Daniel Summerhays' 5-under 65 was the lowest round of the week thus far. It was his best single-round score in a major, topping his 67 at last year's U.S. Open.
"That was a round to remember," Summerhays said. "I need to think a lot about that round, just sear it right into my memory."
Day completed 15 holes in his second round and was 5 over when play was suspended Friday while Mickelson is 7 over through 16 holes in his round.
McIlroy (7 over) and Fowler (6 over) will start their second rounds at 8:39 a.m. on Saturday.
Angel Cabrera, who won the U.S. Open at Oakmont in 2007, is tied for 56th at 5 over for the weekend and completed all but one hole in his second round.
The top 60 players including ties will make the cut for Saturday and Sunday.
NOTES: Phil Mickelson is in danger of missing consecutive major cuts for the first time since the 2007 U.S. Open and The Open Championship. Mickelson also missed the cut at this year's Masters. ... Peter Hanson of Sweden was disqualified on Friday for signing an incorrect scorecard. Hanson, a 38-year-old who is a regular on the PGA European Tour, shot a first-round 77. He is ranked 225th in the world. ... Scottie Scheffler, who will begin his second round at 7 a.m. on Saturday, has the best score among amateurs. Sam Burns, Sam Horsfield of England and Jon Rahm of Spain are the next closest amateurs on the leaderboard, tied for 72nd at 6 over.