Rory McIlroy relinquished his share of the overnight lead in early second-round US Open action on Friday at Pinehurst in North Carolina.
McIlroy, who began the day level with Patrick Cantlay after opening with a five-under-par 65 that left them one shot clear of Swede Ludvig Aberg, went out in the fifth group from the 10th tee and covered the back nine in two-over-par 37.
Cantlay, competing in his 30th major and seeking his first triumph at one of golf's blue-riband events, was alone in front at the time.
World number three McIlroy, who was one of two players to go bogey-free in an opening round where only 15 players managed to break par, saw that clean streak end quickly on Friday.
The Northern Irishman dropped his first shot at the par-four 11th where his approach shot rolled off the green and between two bunkers. He chipped back on and then watched as his par putt from just inside six feet rolled over the right edge.
He then bogeyed the par-three 15th where he failed to get up and down after his tee shot rolled off the false front that protects an otherwise accessible green.
McIlroy looked certain to slip further back at the par-three 17th after his long-range birdie putt rolled off the green but he managed to save par with a brilliant chip from 39 feet that produced a wild roar from the surrounding fans.
He made par at the 18th and began the homeward nine two shots behind Cantlay.
Should McIlroy collect his first major title since the 2014 PGA Championship this week, it would mark the longest gap between wins for any player in US Open history, his 13 years breaking the record 11 shared by Julius Boros and Hale Irwin.
McIlroy has 20 top-10 major finishes without a win over the past decade.
Bryson DeChambeau, the 2020 US Open champion and one of 12 LIV Golf players in the 156-player field, began his day two shots behind the leaders and covered his first eight holes in one over.
Among the other late starters is Frenchman Matthieu Pavon, who also finished the opening round two shots behind the co-leaders and is looking to become the first US Open champion to win in his debut since Francis Ouimet in 1913.
Meanwhile, Sepp Straka made a hole-in-one during Friday's second round, six holes after he hit the flagstick on his way to a triple bogey.
Straka aced the 194-yard ninth hole, with the ball landing on the front portion of the green and rolling about 30 feet into the cup. It was the first ace on the PGA Tour for Straka, who raised his arms in jubilation.
On the short par-4 third hole, Straka's approach from 139 yards banged into the flagstick, with the ball rolling back off the green and into a bunker.
From there, his shot went too far and rolled off the back right side, a rough stretch that ultimately resulted in a triple-bogey 7.
Straka, who was born in Austria and represented Europe in last year's Ryder Cup, shot an even-par 70 in Thursday's first round.
