Bryson DeChambeau eagled his final hole to set the clubhouse lead midway through round two of the US Open at Winged Foot in New York.
His three-under-par total is two behind first-round leader Justin Thomas, who is among Friday’s later starters.
Northern Ireland’s Rory McIlroy started his second round at 18:27 BST on three under par.
Americans DeChambeau and Bubba Watson were the only players to card under-par scores in tough conditions early on.
“I feel like I drove it pretty well considering the windy conditions, it’s super tough,” said DeChambeau, after he carded a two-under-par 68.
Xander Schauffele, one of the favourites to win his first major, birdied the 11th to move to within two shots of Thomas’ lead but three bogeys in his final five holes saw the American finish with a two-over 72 to sit level for the tournament.
South African Louis Oosthuizen had also climbed to within two of the lead but he followed back-to-back bogeys with a double at the last to card a 74 and slip to one over par.
Players enjoyed unusually benign conditions on the opening day at Winged Foot, where Geoff Ogilvy won at five over par in 2006 on the US Open’s last visit to the New York venue, but the West Course began to bite back on Friday.
Despite relatively low scores no player carded a bogey-free round on day one, and difficult pin positions during a windy second round kept scoring at a premium.
Thomas Pieters, who started the day on four under, moved into the lead with two birdies on the front nine, but unravelled after the turn as six bogeys saw him fall back to level par.
“It’s definitely twice as tough as yesterday, with the wind,” said the Belgian after his four-over-par 74.
England’s former world number one Lee Westwood also failed to build on an opening 67, beginning his round with back-to-back bogeys and adding another at the sixth.
A birdie on the par-five ninth offered the 47-year-old some relief, but he dropped four shots in his final three holes for a six-over 76 that leaves him three over par for the week.
Compatriot Tommy Fleetwood, runner-up in 2018, struggled to find any momentum as five birdies were wiped out by nine dropped shots, including a double-bogey at the second, to put him at eight over par.
World number one Dustin Johnson was two under through his opening nine, after starting on the 10th tee, but made successive bogeys after the turn to finish level and remain at three over.
Gary Woodland’s US Open defence continued with a second successive 74 to leave the American at eight over par and likely to miss the cut which is forecast to be six over.
