RORY McIlroy admits he has had "about four’’ hangovers since his runaway US Open victory, but he will not be adding his slow start to the Open to the list.

After three weeks out enjoying his success and then preparing for golf's next major the 22-year-old Northern Irishman, given a huge ovation when his name was called to tee off, fell to two over par after only three holes.

But in the windy conditions McIlroy was happy enough to play the remainder in one under for a 71 that keeps his hopes alive of becoming the youngest winner since Willie Auchterlonie in 1893.

"No hangover,’’ he insisted. "I didn't hit the fairway on the first and it was going to be very difficult to stop it anywhere close to that pin.

"And on three I got a little bit unlucky. I hit the downslope with my tee shot and it ran through the back and into not a great lie.

"I struggled a bit with my speed all day on the greens, but it was a day where you just needed to grind out a score and anywhere around even par was a good start.

"On a day like this - I know better than most people - you can shoot a high number and put yourself out of the golf tournament, so it was nice to go out and shoot a decent score.

"I feel like if you keep it around level par this week you're going to have a good chance.

"The support was great. I probably didn't take it in as much as I could have - I was just trying to concentrate on that first tee shot and get that out of the way.

"But it's fantastic and hopefully I can give them something to shout about.

"I felt relatively calm surprisingly. Usually I do get a few first-tee nerves, but I felt good.’’ From around 70 feet just off the back edge he three-putted the hole, something he did do in the first 70 holes at Congressional, and it was not until the 453-yard eighth that he had his first birdie from eight feet.

He did drop another shot on the 13th, but his approach to the downwind 426-yard 17th came back down a slope to within 10 feet and set up his second and last birdie.

"I was patient, really patient out there - mentally I was very good,’’ he said.

"I felt I could have hit it in the fairway a bit more. I missed a few and from there you can't really give yourself many chances for birdies.

"I holed a few nice putts for par in the middle of the round and that's what you need to do, especially in majors and when you're in tough conditions like this.

"I don't feel as if I have to do that much differently. I just need to keep it tight and just take your birdies here and there.

"It was definitely a round after the start that could have got away from me and it was nice to hang onto it.’’ McIlroy and playing partner Ernie Els did not fail to notice the significance of Thomas Bjorn setting the pace on the course where he could not hold onto a three-shot lead in 2003.

"On the 11th tee we're like 'What is he doing? How is he six under par? Fantastic - great to see him doing well.

"It would be a great story if he could get himself into contention again going into Sunday.’’ Asked if he was now under greater pressure as a major champion McIlroy replied: "It's a nice pressure to have - I'm not complaining.

"I've put myself in this position and it's what I've always wanted to do. If that's the worst complaint that I have I'll be doing all right.’’