Rory McIlroy made a shaky start to his US Open defence today, shooting seven-over-par 77 in the first round at the Olympic Club.
Unlike last year, when he romped to victory with a record-breaking total of 16-under-par at Congressional, the Northern Irishman struggled all day.
He made eight bogeys, including three in his last four holes, and just one birdie to leave himself with a battle just to make the cut, let alone retain his title.
"I tried to approach it like any other tournament I play. I tried to go out there and shoot the best score I could," said McIlroy.
"Today wasn't my greatest day, but hopefully I can come out tomorrow morning and try and shoot a good one and at least try to be here for the weekend."
McIlroy's limp performance could not have been any more different to last year's, when he was a model of efficiency from tee to green and brimming with self-belief.
In 2011, he missed only 10 greens in regulation during the entire tournament but in his opening round on Thursday, he missed 12.
McIlroy was also erratic off the tee and hit the fairway seven of 14 times, cutting a forlorn figure as he trudged off at the last after yet another bogey.
"Too many times, I was just in the wrong position off the tee or with my second shot and it makes it very difficult," he said.
"When you're trying to play catch-up on this golf course it's very hard.
"You have to be so precise. Anything just a little off and it really punishes you."
McIlroy has struggled for consistency since he briefly climbed to the top of the world rankings earlier this year.
Memories of last year's Masters meltdown came flooding back when he finished tied for 40th at Augusta National in April and although he came second at Quail Hollow, the site of his first PGA Tour win in 2010, he missed the cut in his next two events.
The 23-year-old showed some encouraging signs of a timely return to form when he completed his U.S. Open preparations with a tie for seventh at the St Jude Classic last week.
But even that was tinged with some disappointment after he led by two shots on the final day but made a double-bogey on the last hole when he needed a birdie to get into a playoff.
While McIlroy floundered, his countryman Graeme McDowell flourished in the difficult conditions, shooting a 69.
McDowell won the U.S. Open at nearby Pebble Beach two years ago with a four-round total of even par and said McIlroy could not be counted out just because of one bad round.
"If anybody can come back from it, he can," McDowell said.
"He'll be coming out with guns blazing tomorrow trying to get himself back in the mix."
World number one Luke Donald made a disastrous start to the US Open on Thursday, leaving his hopes of winning his first major in tatters after a nine-over-par 79.
The Englishman failed to make a single birdie as he struggled to cope with the notoriously difficult Olympic Club course, which punishes even the tiniest of errors.
Donald finished with the same score as 14-year-old Chinese qualifier Andy Zhang who was so nervous in his major debut that he was trembling on the first tee; and only 13 players shot worse.
"My putter kind of went cold today, otherwise I could have probably ground out some more respectable scores, but this place is tough," Donald said.
Donald was the most consistent golfer in the world last year and finished at the head of the money lists in Europe and the United States.
He has won tournaments on both sides of the Atlantic Ocean this year, yet for all his success the 34-year-old remains dogged by one glaring omission from his CV.
He has finished in the top five at the Masters, British Open and PGA Championship but has never finished in the top 10 at the US Open, which is traditionally set up to be the hardest to play.
"At the US Open, the margins are that much smaller and if you're just a little bit off, which I was today, it's tough," he said.
Donald was in the same group as Northern Ireland's Rory McIlroy, the world number two, and fellow Englishman Lee Westwood, ranked third.
McIlroy bogeyed three of the last four holes for a 77 to leave his title defence hanging on a thread while Westwood carded a 73 after recovering from a double bogey at the first to play the back nine in one-under.
Collectively, the trio were 19-over for the round and managed a combined total of just three birdies.
"That shows how tough it is. There aren't that many opportunities out there," Donald said.
"It's a challenge. I tried to stay patient, tried to stay positive, but when I had those opportunities on the greens I couldn't take them.
"The US Open demands your full attention and obviously Lee had a good back nine, but Rory and I both struggled."