McIlroy will have to put in a big improvement with his putter over the next three days here at Chambers Bay if he is to add to his haul of major championship victories following a two-over-par 72 that left him seven shots adrift of early frontrunners Henrik Stenson of Sweden and American Dustin Johnson on the first day of the 115th US Open Championship.

Yet the Irishman's problems were proving minimal in comparison to former number one and three-time US Open winner Woods, whose latest swing modifications under new coach Chris Como continued to bedevil his competitive play.

Eight years on from his most recent major victory at the 2008 US Open, 39-year-old got off to horrible start by the shores of Puget Sound in America's Pacific Northwest. Woods was four over par just eight holes in to his opening round, his frustration with his game all too plain to see as he slammed his driver into the ground after another errant tee shot at the seventh and then loosened his grip after a poor shot out of the rough on the next hole, sending his iron flying through the air as the ball sailed over the fairway into the rough on the other side.

All facets of his game were misfiring, with Woods missing three of his first seven fairways and four of eight greens, while he was averaging two putts per hole and lagging behind the field average of 1.82.

By contrast, McIlroy's game from tee to green had left the Ulsterman satisfied after an opening round featuring two birdies, four bogeys and 30 putts that sent him back to the practice putting green immediately after the Irishman had completed his post-round media commitments.

“It was frustrating, especially how I felt I hit the ball from tee to green,” McIlroy said. “I drove the ball great. I hit my iron shots very, very well. Even when you hit good iron shot, getting it to 25, 30 feet is a good shot at times. I felt like I gave myself enough chances out there to convert a few and wasn't able to do that.

“Missed a couple of short-ish putts on the last few holes there and definitely thought it was a day where you could shoot under par and I didn't take advantage of that.”

Still, McIlroy felt he could post a low score on Friday if he could iron out his putting issues.

“I definitely think so if I can keep hitting the ball as well as I did off the tee. And if I can hit my irons, I hit a lot of fairways and greens, I just didn't quite have it with the putter today and that's something that I need to get right over the next three days if I want to have a chance.”

Johnson and Stenson did take advantage of the opportunities they created and each shot a five-under-par 65 in the first wave of starters that the second wave had initially struggled to match as their rounds progressed last night.

All except American Ben Martin that is, the playing partner of Ireland's Shane Lowry leading the chase at four under after eight holes while the Offalyman was one under having started at the 10th tee. Branden Grace was another late starter enjoying the afternoon heat on a still day with little breeze, even at the higher elevations of the links course south of Seattle.

South African Grace was three under after 10 holes.

McIlroy, a three-time winner this season already but coming into this week's second major of the year on the back of consecutive missed cuts at Wentworth and Royal County Down, had got his championship off to a solid start from the 10th tee. He parred the first and then got up and running with a birdie at the par-three 11th, an excellent tee shot rolling back to eight feet from the hole, from where he sank the birdie putt.

The putting woes kicked in four holes later, however, McIlroy three-putting for bogey at the par-four 15th to fall back to level par. At the next, the par-three 16th, the Irishman was bunkered off the tee and then produced an excellent rescue shot with his sand wedge only to miss his par putt from five feet.

Again at the eighth, he caught a bad break when his approach shot caught the wrong side of a ridge and rolled off the green into a collection area but onece more produced an excellent comeback, lofting his chip back to six feet under the hole. And yet again he missed the putt, this time a birdie eluding the world number one.

It was a frustrating day for his compatriot Graeme McDowell also who slumped to four-over-par 74 having doubled bogeyed the 10th, also his first hole, the start of a long and frustrating round for the former US Open champion from Portrush.

Nothing could have been further from the experience Dustin Johnson was enjoying at the other end of the leaderboard, despite a disappointing end to his opening round with his first bogey of the day at the par-three ninth, which was being played with the USGA using its lower teeing ground rather than the more dramatic upper one which involves a 100-foot drop down to the undulating green.

Johnson found waste ground short of the green with his uphill tee shot and would be denied his first bogey-free round at a US Open.

“I'm very pleased with my round today,” the American said. “I thought I played really solid all day. Obviously the bogey at nine, I hit a poor tee shot there. And hit a really good chip to even have a 15-footer for par and hit a good putt, just came up a little bit short. All in all I thought I had a great day.”

Sweden's Stenson, the world number six, was equally enthused with his opening day's work particularly his patience, joining Johnson in the clubhouse on 65 soon after the American had completed his round.

“I'm very pleased with the day's work. All in all, I played solid. Gave myself some nice birdie chances coming in and just rolled a couple of beauties in from 14 and onwards. Pleased with the striking and putting the way I played the round.”

In the clubhouse a shot behind the leaders was Texan Patrick Reid with fellow American Matt Kuchar a further shot behind after a 67. Scotland's US Senior Open champion Colin Montgomerie finished with a one-under 69 as did fellow veteran Miguel Angel Jimenez and 45-year-old Phil Mickelson, while Bubba Watson finished on level par and defending champion Martin Kaymer on two over alongside McIlroy. Masters champion Jordan Spieth was level par after 10 holes.