Rory McIlroy plays his shot on the 10th hole during the first round of the 2025 U.S. Open at Oakmont Country Club in Oakmont, Pa. on Thursday, June 12, 2025. (Logan Whitton/USGA)

Rory McIlroy went out on a magic carpet of sheer brilliance but joined Shane Lowry in coming home in an ambulance as Oakmont punished Irish golf's twin stars in the 125th US Open.

Lowry was behind the eight-ball all day as he went to the turn in four-over 39, then came home in 40, hitting only eight greens in regulation en route to a nine-over 79 that matched his highest US Open round.

The Offaly man had 31 putts, but that tally does not explain that he chipped in for par at the driveable 17th and spectacularly holed a 160-yard approach for the first eagle two ever recorded in an Oakmont US Open at the infamous third hole.

McIlroy's 74 was bitterly disappointing after he had played some spectacular and spirited golf to cover his opening nine holes, Oakmont's back nine, in two-under 33.

Pre-tournament worries about his demeanour and his driving looked misplaced as he played the kind of golf that brought him Masters glory just two months ago.

Oakmont's huge, titled greens are utterly intimidating and after three-putting the first to slip back to one-under and escaping with a miraculous bogey six from 30 feet at the 611-yard fourth, he dropped four shots in his last four holes and declined to speak after his round.

Shane Lowry plays his shot on the 10th hole during the first round of the 2025 U.S. Open at Oakmont Country Club in Oakmont, Pa. on Thursday, June 12, 2025. (Logan Whitton/USGA

His 74, which featured 34 putts, left him eight shots behind JJ Spaun, the man he defeated in a playoff for The Players Championship at Sawgrass in March.

The American (34) shot only the eighth bogey-free round recorded in a US Open at Oakmont — a four-under 66 that gave him a one-shot lead over the big-hitting South African Thriston Lawrence and two strokes to spare over Korea's Si Woo Kim.

Of those who went bogey-free before him, only Ben Hogan and Dustin Johnson went on to win here. Like Spaun, their bogey-free efforts also came on day one at the storied Pittsburgh venue, where bright sunshine and a light breeze sped up the course and made the glassy greens a penal test.

That it is Spaun's first visit to Oakmont and only his second US Open clearly helped him block out the dire pre-tournament warnings of Oakmont carnage.

"I came out here with no prior history at Oakmont, not really knowing what to expect, even US Open-wise," Spaun said. "This is only my second one.

"I don't know if that freed me up in any aspect, but I just tried to take what the course gave me."

Spaun also scrambled like a demon, getting up and down six times out of six for par compared to just three out of 10 for Lowry and two out of five for McIlroy, whose recent driving woes were almost non-existent until he reached the fourth (his 13th) and carved his tee shot right into deep jungle.

Lucky to find his ball, he managed to hack it 20 yards as far as the grassy upslope of a fairway bunker but moved his third just 10 yards.

He looked destined to make a big number, but after hitting his fourth to the fairway, he fired a 178-yard fifth to 30 feet and made the putt for a bogey that smacked of glory.

It turned out to be the start of a slow bleed to the finish as he missed a six-footer for a sand save par at the short sixth and three putted the seventh before racking up a double bogey at the 276-yard eighth, where his three wood sailed into deep rough on the right, and he could only hack it a few feet forward.

It was all such a contrast to the front nine, where he missed a slippery nine-footer for an opening birdie at the 10th but made a 25-footer at the 11th and took advantage of a massive 392-yard tee shot at the par-five 12th, where Lowry dropped his first shot of the day after tangling with the heavy rough.

McIlroy two-putted from 50 feet for his four there, making an eight-footer, and shaved the hole with another birdie chance at the short 13th.

When required to dig deep, he got up and down for par from short of the green at the dangerous 15th, making a seven-footer, and made another seven-footer for par at the drivable 17th.

It all looked promising before Oakmont bit back and it was an even tougher day for Lowry, whose pre-tournament admission that his play on and around the greens is the reason he hasn't won individually since the 2023 BMW PGA at Wentworth.

A double bogey at the 222-yard 16th, where he overshot the green from sand and missed from six feet for par, sapped his confidence.

Another blow came at the 18th, where his approach from the fairway failed to cover the false front and rolled back down the hill, 56 yards from the pin.

He made a bogey there, but it was a double bogey when he suffered a similar fate at the 356-yard second, spinning his second off the green before compounding his mistake by three-putting.

Even when he holed out from 160 yards for a two at the third to get back to four-over, he missed five putts between six and eight feet on the next five greens and dropped five shots.