Dustin Johnson set the clubhouse target midway through the second round of the US Open at Oakmont Country Club but Lee Westwood, Sergio Garcia and Shane Lowry will be looking to rein him in on Saturday morning.
Storms and torrential rain on Thursday and into Friday meant that half the field will begin their second rounds on Saturday with joint leader Andrew Landry among those yet to complete 36 holes.
The World Number 624 played just a single shot on Friday as he rolled in a ten-footer for a 66 - the lowest first round in US Open history at Oakmont - while Johnson played 36 holes on day two in Pennsylvania.
The big-hitting American recorded rounds of 67-69 on Friday to get to four under and catch Landry but he could not overturn his countryman despite some brilliant work off the tee and excellent iron play.
Johnson did not drop a shot in his first 27 holes as he saw birdie putts brush the hole but gains on the 13th and sixth in his second round helped move him to the top of the leaderboard.
"It was a long day today but I felt like I played really solid all day for all 36 holes," he said. "I drove it really well, hit a lot of great iron shots. I felt like I rolled the putter really nicely too. So I'm very pleased with how it went today.
"I hit so many good putts today that I thought were going in and burned the edge or lipped out. But that's just how it goes. I mean, these greens are tough.
"I felt like I was doing everything correct. I was hitting all my putts where I wanted to. They're going to go in eventually, but I made some nice putts too.
I'm happy with the way everything went today - Dustin Johnson
Westwood sat a shot off the leaders as he finished birdie-birdie in the remaining five holes of his first round, putting his tee-shot to 12 feet on the huge par three eighth and then his approach to five feet on the ninth.
The Englishman, who has finished in the top three twice at this event, will tee-off at 8.28am in the second round as the tournament gets itself back on track for a Sunday finish and he goes in search of a first Major Championship.
Garcia went round twice on Friday and he completed rounds of 68-70 - with the help of a brilliant 51-foot putt to save par on the ninth in round two.
The Spaniard is two under alongside Irishman Shane Lowry, who tees off at 8.50am after an opening 68.
American Scott Piercy is also at two under after rounds of 68-70, a shot clear of a group of seven players including Englishman Andy Sullivan.
Sullivan recorded four birdies in a second round 68 as he found some momentum after a disappointing season so far by his very high standards.
Daniel Summerhays fired a brilliant second round of 65 to also get to one under alongside Danny Lee, amateur Scottie Scheffler, Kevin Streelman and Bubba Watson who had all played 18 holes.
Jim Furyk, champion in 2003, was also at that mark after 35 holes and will return to complete the ninth at 7.15am after play was suspended due to darkness.
Lee Slattery went 72-68 to sit in the group at level par with Russell Knox, who had completed just one round.
French duo Grégory Bourdy and Romain Wattel were at one over after opening 71s, a shot clear of defending champion Jordan Spieth.
Masters Tournament winner Danny Willett was at five over, two shots clear of 2011 champion Rory McIlroy with both men having completed 18 holes.
