Rory McIlroy, seeking an elusive fifth major title, relinquished his share of the overnight lead in early second-round U.S. Open action on Friday in North Carolina where the notoriously tricky Pinehurst No. 2 layout bared its teeth.

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 and scheduled to tee off at 1:25 p.m. ET (1725 GMT).

Masters runner-up Aberg, who hit every fairway at Pinehurst No. 2 in the opening round, will be a further group behind.

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.

Belgian Thomas Detry, three under through his first four holes, was a shot off the lead while Englishman Tyrrell Hatton, one under through eight, was a further shot back.

Bryson DeChambeau, the 2020 U.S. 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 U.S. Open champion to win in his debut since Francis Ouimet in 1913.

Pre-tournament favourite Scottie Scheffler, who began the day in a share of 34th place, was playing with McIlroy and was two over on a day during which he threw his putter in frustration after a missed birdie putt at the 15th.

Tiger Woods, competing in only his fourth event of the year, is at risk of missing the cut after struggling to an opening-round 74 and will tee off at 1:14 p.m.

The top 60 players and ties will make the cut.

(Reporting by Frank Pingue in Toronto; editing by Clare Fallon)