ERIN, United States - Rory McIlroy made the fast start he was looking for at the US Open on Thursday but ended up trundling over the finish line after a back nine collapse.

The world number two from Northern Ireland, desperate to add to his collection of four majors, was left fighting for survival at Erin Hills after a six-over-par first round 78.

An early eagle was wiped out by four bogeys and two double bogeys, meaning McIlroy now must produce something special on Friday to extend his stay in 

Wisconsin into the weekend.

McIlroy blamed his wayward play from the tee for his problems.

"It all started so well," McIlroy said. "I don’t think I hit a fairway from the 10th. You cannot play this golf course if you’re not in position off the tee, and I wasn’t in position. Obviously, I paid the price for it today."

McIlroy, who had spoken of his need to make a strong start in his quest for a fifth major, was as good as his word. The problem however was that it only lasted two holes.

A straightforward par on the first was followed by a superb eagle on the 330-yard par-four second where McIlroy’s length off the tee came to the fore.

After comfortably reaching the green in one, McIlroy rolled in a brilliant 27-foot putt for an eagle two.

Yet rather than act as the catalyst for a low-scoring round, McIlroy’s momentum stalled on the next hole when he three-putted for bogey.

A further bogey on the eighth saw him drop back to level par, leaving him off the pace.

But it got worse on the back nine, when bogeys on the 11th and 13th were followed by two double bogeys on 15 and 17.

McIlroy, who is returning from a niggling rib and back injury, insisted that his fitness was not the issue.

"I feel great. That’s all totally fine," he said of his injury.

"I was hacking around in the rough out there and didn’t feel it one bit. 

So, no, that’s totally fine.

"Just timing was a little bit off, and that was it. Just really bad tee shots which led to obviously not being able to give myself many looks for birdies. -- AFP