McIlroy (-1) watches his birdie putt on 12 slip underneath the hole. Half a ball under the line.

McIlroy (-1) had just 137 yards for his second shot and nudges a wedge into 14 feet.

Lowry (+6) endured the horrors on the second, his 11th hole. Came up short with his second, and took four to get down. Detry (-3) joins Woodland in second place.

Ha ha sport. EAGLE. Lowry (+4) then promptly holes his second shot to the 12th from 180 yards. The sheepish smile.

Scott (-1) drops a shot on 12. Spaun (-4) catches the grass on the verge of a fairway bunker on 13. McIlroy (-1) takes driver on 11, catches the rough but plays a good recovery shot to about 15 feet. 10 players are under par.

LEADERBOARD

-4 Spaun (12)

-3 Woodland (9)

-2 Aberg (12), Scott (11), Clark (8), SW Kim (9), Detry (7)

Irish scores

-1 McIlroy (10)

+4 Lowry (10)

BOGEY. McIlroy (-1). Following a brilliant tee shot he’d only 125 yards for his second but he got too much spin, it finished short on the pin and backed up to about 16 feet. It meant that he was putting down the slope. He watched his putt roll five feet past and missed coming back. That’ll hurt. A lot. Lowry (+4) has no such problems. A par for the Offaly man.

Good scrambling from the leader Spaun (-4) on his 12th earns him a par.

McIlroy (-2) starting on the 10th, turns in two under, after cleaning up for par on the 18th. He now heads for one of the toughest holes on the course, the first. Lowry (+4) missed his approach to the green on 18 and it cost him a bogey. Two bogeys and a double on the par three, 16th have made for a frustrating front nine.

LEADERBOARD

-4 Spaun (10)

-3 Woodland (8)

-2 McIlroy (8), Scott (9), Clark (6), SW Kim (8), Norgaard (5), Detry (6)

Irish scores

+3 Lowry (8)

The greens at an average PGA Tour event venue run about 12 on the Stimpmeter, Oakmont are running 15.

McIlroy (-2) from 182 yards, stripes his eight iron but comes up about four inches from the top of a slop to the pin. His ball rolls back a bit but he’s still inside 15 feet.

Aberg (-1) drops a shot on the first, his 10th. DeChambeau (level) watches his par putt horseshoe out on the ninth.

Lowry (+3) finds the fairway and from 208 fans a five iron that lands on the green but rolls back 30-yards off it.

LEADERBOARD

-4 Spaun (10)

-3 Woodland (7)

-2 McIlroy (8), Scott (9), Aberg (9), Griffin (8), Clark (6), SW Kim (6), Norgaard (5), Detry (6)

Irish scores

+3 Lowry (8)

PAR. Huge from McIlroy (-2), rolls in the par putt. Thomas Detry joins the cluster of players on two under.

Eight feet for McIlroy (-2) for par. Mistake was from the three wood tee shot. Brilliant. Lowry (+3) chips in for par.

This refers to an incident earlier in DeChambeau’s round.

DeChambeau (-1) with a huge drive and then putts from the fairway down the hill. McIlroy (-2) had a horrible lie and catches the bunker with his second. Lowry’s (+3) lie is even worse. He moves it three feet. Please bear in mind that Lowry has a brilliant short game. The rough is ridiculously penal.

McIlroy (-2) and Lowry (+3) both find the heavy rough at the driveable par four, 17th. Aberg (-2) and Scott (-2) birdie the ninth to join the tie for third place.

LEADERBOARD

-4 Spaun (9)

-3 Woodland (6)

-2 McIlroy (7), Clark (6), SW Kim (6), Norgaard (4)

Irish scores

+3 Lowry (7)

Two-time and defending US Open champion DeChambeau (-1) gets into red figures with a second birdie in three holes at the seventh. Xander Schauffele (+2) makes a double bogey.

McIlroy (-2) shoves his birdie putt on the 16th a good four feet past but tidies up nicely. DOUBLE BOGEY. Lowry (+3) has his problems on the same hole, starting with catching a greenside trap, de-greening it and taking three more from there.

Spaun (-4) leads the US Open, four under to the turn. Big hitter Niklas Norgaard (-2) gets to two under after four holes.

LEADERBOARD

-4 Spaun (9)

-3 Woodland (5)

-2 McIlroy (6), Clark (5), SW Kim (5)

Irish scores

+1 Lowry (6)

Woodland (-3) makes it three birdies in his first five holes.

Spaun (-4) with another birdie on the 17th, his eighth. McIlroy (-2) takes the aerial route with his chip shot. He’ll have five feet for par. Lowry (+1) can’t convert his birdie effort but his chip was a beauty and nearly went in. McIlroy’s (-2) putt grabs the right edge and drops in.

McIlroy (-2) gouges out his second to the 15th and runs the ball up to the front apron. That was a super effort. Lowry (+1) has no such problem, striping his tee shot down the centre of the fairway.

McIlroy (-2) with a fine two-putt but then pushes his tee shot into the heavy rough on the 15th. Spaun (-3) claims the outright lead with a birdie on the 16th. Defending champion DeChambeau (levels) mkaes up for a bogey on the first with a birdie on the fifth. He enjoyed some good fortune with his second shot. Lowry (+1) couldn’t take that birdie chance.

LEADERBOARD

-3 Spaun (7)

-2 McIlroy (5), Woodland (4), SW Kim (4), Clark (4)

Irish scores

+1 Lowry (5)

Lowry (+1) will have 12-feet for birdie. McIlroy (-2) caught the fringe in front of the bunker but hit a chunky chip and will have a long range birdie putt. He’d be happy to get down in two. Si Woo Kim joins McIlroy and Spaun at the top of the leaderboard.

Lowry (+1) makes par on the 13th and on the short par four, 14th, his tee shot comes up 103 yards from the green. McIlroy (-2) catches a bunker 71 yards from the green. DeChambeau (+1) is one over through four holes.

McIlroy (-2) gives himself a birdie look on the par three, 13th and rolls a lovely putt with a huge break down to 12-inches. Superb.

LEADERBOARD

-2 McIlroy (3), Spaun (5)

-1 Aberg (5), Woodland (3), Scott (5), Cole (5), Kim (5), Clark (3), SW Kim (2)

Irish scores

+1 Lowry (3)

BIRDIE: McIlroy (-2) makes the most of the chance. Touches his first putt into the centre of the hole. That’s a fitting reward for two brilliant shots en route to the green on the par five.

McIlroy (-1) runs it past from 52-feet for eagle. That’s not what he wanted. He’ll be coming back down the hill. His facial expression said everything. A grimace. Lowry (+1) makes a bogey. Tee shot found the rough, second a bunker, third came up short and he failed to get up and down.

McIlroy (-1) is playing a 618 yard par five 12th, he thumped his drive 392 yards, his a six iron 227 yards, watched the ball land 10 feet short of the hole on a green that runs front to back and saw his golf ball role another 20 feet. Obscene. Lowry (level) caught a bunker with his second and then from 94-yards caught his trap shot a little heavy. coming up short.

McIlroy (-1) unsheathes the driver for the first time on the 12th and sends a bomb down the fairway that runs for miles. Or 394 yards to be precise. Lowry (level) also finds the fairway…….just the 362 yards.

LEADERBOARD

-2 Spaun (3)

-1 McIlroy (2), Aberg (3), Woodland (1), Scott (3), Cole (5)

Irish scores

Level Lowry (2)

JJ Spaun (-2) birdies the third to join Aberg at the top of the leaderboard but the Swede is in a bit of trouble. He bogeys the 12th, his third to drop back to one under.

Right on cue. BIRDIE. McIlroy (-1) gets his round going at the 11th, his second holing a 20-footer. Lowry (level) from a similar distance of about 19-feet watches his birdie attempt slide by.

Rory McIlroy hits a tee shot on the 10th hole during the first round of the 125th US OPEN at Oakmont Country Club. Photo: Andy Lyons/Getty ImagesRory McIlroy hits a tee shot on the 10th hole during the first round of the 125th US OPEN at Oakmont Country Club. Photo: Andy Lyons/Getty Images

McIlroy (level) hits the centre of the fairway at the 11th and promptly watches his ball roll off into the first cut.

LEADERBOARD

-2 Aberg (2)

-1 Fitzpatrick (1), Moldovan (2), Spaun (2)

Irish scores

level Lowry (1), McIlroy (1)

Tommy Fleetwood has had to take a couple of penalty drops off his first brace of tee shots.

McIlroy (level) touches his birdie putt and it just shaves the right edge as it slips past. That was slick. He tidies up for par. Lowry’s (level) ball must have come back a bit because his birdie putt was 52-feet, which he cosied down to about two and them cleaned up as did Rose (level)

Defending champion Bryson DeChambeau (+1) bogeys the first. Adam Scott (level) with a bogey, birdie start from the 10th.

Rose does brilliantly to make the front edge of the 10th green from the rough. Lowry tugs his approach to about 80 feet. McIlroy (298 yards off the tee with a long iron) hits a gorgeous approach to about nine feet under the pin.

Among the early starters, Moldovan (-2) is one shot clear of a trio including Sweden’s Ludvig Aberg (-1).

Shane Lowry, who led going into the last round the last time the US Open was played at Oakmont finds the fairway on 10 with his opening drive. Justin Rose pulls his into the left into the rough. McIlroy, taking an iron, finds centre cut on the fairway.

Right time for the serious stuff.

Maxwell Moldovan (-2) leads the US Open after holing out with his second shot from 189 yards to the par four first.

10 minute warning. Rory McIlroy and Shane Lowry will shortly be making their way to the 10th tee, their first hole to start the first round of the US Open.

The inestimable Philip Reid is our man at Oakmont. Here is some of his finest work.

[ Philip Reid previews the US OPenOpens in new window ]

Ron Driscoll, a contributing editor for the USGA interviewed Jeff Hall who has been involved in course set-up for the USGA for the four US Opens at Oakmont since 1994.

Hall said: “When you look at Oakmont, one of the unique aspects is that there are several holes where the putting green runs from front to back. And when it’s firm and you put green speeds in the upper 14s, you’re likely going to have to pitch your ball well short of the green to keep it on. Those are shots you might see in the British Open, but certainly not coupled with these green speeds.”

The greens on Nos. 1, 10, 12 and 15 all feature significant front-to-back slopes. Depending on how firm the conditions get, it could also make several of the undulating fairways much harder to find once the ball hits the ground running.

“It’s a wonderful driving golf course that requires an attention to detail that’s really exquisite,” said Hall. “All in all, I would argue that Oakmont is one of the great mental tests that we conduct the US Open on.

“It’s so hard to stay patient; you’re working so hard to put the ball in the proper place on these greens, and suddenly, you find yourself 10 feet above the hole facing a putt that might break 2 feet. It’s a complete examination – physically, mentally, emotionally – and if you have a weakness in your game, it will expose it.”

The first shot was struck by former Oakmont caddie and current full-time dentist Matt Vogt.

Just thought I’d slip this in for the rugby fans.

Not long to go now

Find your favourites and their tee times.

TEE TIMES (US unless stated, * denotes amateur)

Off 1st tee (10th tee Friday times in brackets)

11.45am (5.30pm) Matt Vogt (a), Kevin Velo, Trent Phillips

11.56am (5.41pm) Chandler Blanchet, Alvaro Ortiz (Mex), Doug Ghim

12.07pm (5.52pm) Evan Beck*, Maxwell Moldovan, Justin Hicks

12.18pm (6.03pm) Harris English, Tommy Fleetwood (Eng), Keegan Bradley

12.29pm (6.14pm) Xander Schauffele, Jose Luis Ballester Barrio (Esp), Bryson DeChambeau

12.40pm (6.25pm) Matt Fitzpatrick (Eng), Wyndham Clark, Gary Woodland

12.51pm (6.36pm) Akshay Bhatia, Matt McCarty, Robert MacIntyre (Sco)

1.02pm (6.47pm) Cam Davis (Aus), Davis Thompson, Thomas Detry (Bel)

1.13pm (6.58pm) Richard Bland (Eng), Trevor Gutschewski*, Lanto Griffin

1.24pm (7.09pm) Edoardo Molinari (Ita), Sam Stevens, Ryan Gerard

1.35pm (7.20pm) Thriston Lawrence (RSA), Noah Kent*, Thorbjørn Olesen (Den)

1.46pm (7.31pm) Jinichiro Kozuma (Jpn), Cameron Tankersley*, Chase Johnson

1.57pm (7.42pm) Philip Barbaree, Riley Lewis, Brady Calkins

5.30pm (11.45am) Frederic LaCroix (Fra), Emiliano Grillo (Arg), Sam Bairstow (Eng)

5.41pm (11.56am) Byeong Hun An (Kor), Joe Highsmith, Ryan Fox (NZ)

5.52pm (12.07pm) Victor Perez (Fra), Jacob Bridgeman, Adam Schenk

6.03pm (12.18pm) Min Woo Lee (Aus), Justin Thomas, Brooks Koepka

6.14pm (12.29pm) Sam Burns, Nico Echavarria (Col), Denny McCarthy

6.25pm (12.40pm) Viktor Hovland (Nor), Collin Morikawa, Scottie Scheffler

6.36pm (12.51pm) Corey Conners (Can), Jason Day (Aus), Patrick Reed

6.47pm (1.02pm) Joaquin Niemann (Chl), Bud Cauley, Daniel Berger

6.58pm (1.13pm) Mackenzie Hughes (Can), Tony Finau, Chris Kirk

7.09pm (1.24pm) Ben James*, Rasmus Højgaard (Den), Stephan Jaeger (Ger)

7.20pm (1.35pm) Rasmus Neergaard-Petersen (Den), Justin Hastings (Cym)*, Laurie Canter (Eng)

7.31pm (1.46pm) Frankie Harris*, Emilio Gonzalez R (Mex), Roberto Díaz (Mex)

7.42pm (1.57pm) Grant Haefner, Joey Herrera, George Kneiser

Off 10th tee (1st tee Friday times in brackets)

11.45am (5.30pm) Zac Blair, Scott Vincent (Zim), Alistair Docherty

11.56am (5.41pm) Jacques Kruyswijk (RSA), Jordan Smith (Eng), Eric Cole

12.07pm (5.52pm) Tom Kim (Kor), JJ Spaun, Taylor Pendrith (Can)

12.18pm (6.03pm) Ludvig Åberg (Swe), Adam Scott (Aus), Hideki Matsuyama (Jpn)

12.29pm (6.14pm) Ben Griffin, Andrew Novak, Maverick McNealy

12.40pm (6.25pm) Shane Lowry (Irl), Justin Rose (Eng), Rory McIlroy (N Irl)

12.51pm (6.36pm) Patrick Cantlay, Si Woo Kim (Kor), Lucas Glover

1.02pm (6.47pm) Cameron Smith (Aus), Brian Harman, Phil Mickelson

1.13pm (6.58pm) Niklas Norgaard (Den), Brian Campbell, Justin Lower

1.24pm (7.09pm) Davis Riley, Jackson Koivun*, Johnny Keefer

1.35pm (7.20pm) James Hahn, Mark Hubbard, Michael La Sasso*

1.46pm (7.31pm) Joakim Lagergren (Swe), Mason Howell*, Chris Gotterup

1.57pm (7.42pm) Zach Bauchou, Jackson Buchanan, Lance Simpson*

5.30pm (11.45am) Will Chandler, Andrea Pavan (Ita), Takumi Kanaya (Jpn)

5.41pm (11.56am) Bryan Lee*, Guido Migliozzi (Ita), Preston Summerhays

5.52pm (12.07pm) Erik van Rooyen (RSA), Max Greyserman, Matt Wallace (Eng)

6.03pm (12.18pm) Russell Henley, Christiaan Bezuidenhout (RSA), Nick Taylor (Can)

6.14pm (12.29pm) Jordan Spieth, Jon Rahm (Esp), Dustin Johnson

6.25pm (12.40pm) Tyrrell Hatton (Eng), Sungjae Im (Kor), Sepp Straka (Aut)

6.36pm (12.51pm) Cameron Young, Tom Hoge, JT Poston

6.47pm (1.02pm) Jhonattan Vegas (Ven), Michael Kim, Matthieu Pavon (Fra)

6.58pm (1.13pm) Marc Leishman (Aus), Aaron Rai (Eng), Nick Dunlap

7.09pm (1.24pm) Matthew Jordan (Eng), Yuta Sugiura (Jpn), Carlos Ortiz (Mex)

7.20pm (1.35pm) Ryan McCormick, Trevor Cone, Zachery Pollo*

7.31pm (1.46pm) James Nicholas, Tyler Weaver (Eng)*, Riki Kawamoto (Jpn)

7.42pm (1.57pm) Austen Truslow, Harrison Ott, George Duangmanee

At the last two U.S. Opens at Oakmont, in 2007 and 2016, missing the short grass was penal. The fairways were framed by six feet of intermediate cut, mown to roughly 1 inch, which gave way to 20 to 25 feet of graduated cut, mown to a height of three and-a-half inches. Beyond that graduated cut was the rough itself, some five inches or higher.

This year the graduated cut has been eliminated. The intermediate cut will transition immediately to full-blown rough, kept at a uniform five inches. Some of that rough might be more trampled-down by spectators than others. But if a drive strays beyond the short grass, it is bound to be in a world of hurt.

Don’t take our word for it. Justin Thomas relayed the following story to Golf Digest. “It’s not like every time you hit it in the rough, you’re grabbing lob wedge and hit it out,” he said after his practice round on Monday. “You have to think, how far can I hit this?”

Thomas saw this first-hand from his Monday playing partner, Jackson Koivun, a rising junior at Auburn University. “Jackson had a lie on 15 today that we were kind of thinking, is it a 6-iron? Open up a 6, or could you hit 7?” Thomas said. “He tried to hit 6-iron, and it looked like he could, and he hit it like four feet in front of him.”

This quote from Jack Nicklaus is very instructive. “A difficult golf course eliminates a lot of players,” the four-time champion said. “The US Open flag eliminates a lot of players. Some players just weren’t meant to win the US Open, and a lot of them know it.”

To scare young golfers with aspirations of making a career as a professional pictures of the rough at a US Open venue are shown to determine if they have the moral fibre to take on the physical challenge.

Oakmont is a doozy of that genre. Henry C Fownes, founder and designer, built a monster, the prevailing conditions, firm, fast, heavily sloping greens with rough in which you could lose a toddler. The rain of recent days at the venue have made the greens a little kinder but the rough is lush and punitive.

That’ll be the front nine for the Irish pairing shortly.

Hello and welcome to the Irish Times live golf blog of the 125th US Open from Oakmont Country Club. John O’Sullivan here and I’ll take you through several hours of play before handing over to Ciarán Kirk in the late afternoon.

US Masters champion Rory McIlroy and Shane Lowry will play together for the first two rounds. The Irish duo have been drawn to play together at 12.40pm Irish time and at 6.25pm on Friday (1.25pm local) alongside former champion Justin Rose.

The good friends, who have won six Majors between them, practised today at Oakmont and won a PGA Tour team event together in New Orleans last year. They start on the 10th tee. World number one Scottie Scheffler will play with Viktor Hovland and Collin Morikawa at 6.25pm on Thursday and 12.40pm on Friday.

The 125th edition of the US Open gets underway this morning as 156 players prepare to navigate their way around Oakmont Country Club in Pennsylvania in what world number one Scottie Scheffler described as “probably the hardest golf course that we’ll play, maybe ever”.

Irish eyes will be on Rory McIlroy and Shane Lowry who are paired together, along with Ryder Cup teammate Justin Rose and will tee-off at 12.40pm.

We will bring you updates from around the course throughout the day and update our leaderboard below as rounds begin.

Notable tee times

12.29pm: Xander Schauffele, Jose Ballester, Bryson DeChambeau

12.40pm: Rory McIlroy, Shane Lowry, Justin Rose

6.25pm: Viktor Hovland, Collin Morikawa, Scottie Scheffler

What are today’s tee times?

Rory McIlroy and Shane Lowry will play together for the first two rounds of the US Open at Oakmont Country Club.

The Irish duo will go off the 10th tee at 12.40pm Irish time today(7.40am local), and off the first tee at 6.25pm on Friday (1.25pm local) alongside former champion Justin Rose.

World number one Scottie Scheffler will play with Viktor Hovland and Collin Morikawa at 6.25pm on Thursday and 12.40pm on Friday.

Selected tee times

First round (US unless stated)

Off 1st tee (10th tee Friday times in brackets)

12.29pm (6.14pm) Xander Schauffele, Jose Luis Ballester Barrio (Esp), Bryson DeChambeau

6.25pm (12.40pm) Viktor Hovland (Nor), Collin Morikawa, Scottie Scheffler

Off 10th tee (1st tee Friday times in brackets)

12.18pm (6.03pm) Ludvig Åberg (Swe), Adam Scott (Aus), Hideki Matsuyama (Jpn)

12.40pm (6.25pm) Shane Lowry (Irl), Justin Rose (Eng), Rory McIlroy (N Irl)

6.14pm (12.29pm) Jordan Spieth, Jon Rahm (Esp), Dustin Johnson