Rory McIlroy curbed his volcanic instincts to dig deep and survive the cut at Turnberry.

The sometimes hot-headed Ulsterman, 20, looked ready to explode as he spiralled to five over for the day after just ten holes.

Ailsa Craig - the island consists entirely of a volcanic plug of an extinct volcano.But he kept his cool to add a four over par 74 to his opening 69 and keep his hopes alive of becoming the youngest winner of the Claret Jug for more than 100 years.

Believing he is now a cooler customer than ever, McIlroy said: “This time last year or 18 months ago I would have thrown it away and missed the cut. I am happy the way I hung in and stayed around and it was nice to make a couple of birdies on the way in.

“I hit a great shot on 18 and I had a 30 footer down the hill and downwind for birdie. It was nice just to see it run up to a foot and tap it in. I didn't want to be grinding over a four footer trying to make the cut.”

One of the early starters, McIlroy was birdied the first to get to two under par but bogeyed the second and fourth before shedding two shots at the fifth where he three-putted for a six after slamming his approach into a greenside bunker.

Red-faced after that error, he was seriously miffed when another shot went at the eighth after he had bunkered his drive.

Far too wayward off the tee this week to have a realistic chance of contending, he found more trouble off the tee on the 10th and bogeyed there to slip to five over for the championship and outside the projected cut mark.

The early holes were playing into the teeth of a strong breeze that gusted over 20 mph but McIlroy took advantage of the downwind homeward stretch to survive for the weekend.

After a tidy birdie three at the 13th, he was frustrated to hand back that shot by three-putting the next.

With eight birdies, seven bogeys and two douuble bogeys so far this week, he said: “That was a bit of a set back because I had just birdied 13 to get back on it and bogeyed straight after.

“That has been the story of the week. I have been making birdies and bogeys all over the place. I've just not been able to get a good run or some momentum.”

He birdied the par-five 17th to ease his worries and then parred the last with two superb strikes setting up an outside birdie chance.

Declaring he never got frustrated, McIlroy said: “I thought I played okay but threw a couple of shots away. It was just a bit of an untidy round but there are still a lot of positives to take from it.

“I didn’t get too frustrated because I knew it was going to be tough for everyone and I was sure that no one was going to be lighting it up out there. I knew that if I could grind it out and shoot three or four over like I did.”