McIlroy holds a four-stroke lead over American Dustin Johnson after a second successive 66 elevated him to 12 under par.

If he can replicate over the final two days anything close to the form he has shown over the first couple he will not only be three-quarters of the way to a personal landmark he will become the third player after Jack Nicklaus and Tiger Woods to win three majors by the age of 25.

The Northern Irishman, who has already won the US Open and US PGA, put any fears about his ’Freaky Fridays’ to bed in impressive style.

“I just feel like I have an inner peace on the golf course. I’m very comfortable in this position, doing what I’m doing right now,” he said.

“It’s hard to describe. I wish I could get into it more often. It’s a combination of confidence, just being mentally strong, mentally aware of everything.

“I think it all comes down to if you’re confident with your game and you’re in control of your ball out there it makes things a lot easier.

“I just take it as I feel it. I’ve got a couple of little trigger words that I’m using this week that I keep telling myself in my head when I’m just about to hit it, go into a shot.

“That’s as complex as it gets in my head. People call it the zone; it’s just a state of mind where you think clearly.

“My second rounds this year have been terrible and there isn’t really any explanation but hopefully I put it to bed.”

While McIlroy enjoyed serene progress at the top of the leaderboard, 14-time major winner Woods, the last man to lift the Claret Jug at Hoylake in 2006, was having struggles at the other end of the scale.

The American, playing in only his second tournament since back surgery in March, required a birdie at the last to make the cut at two over.

His driving is still a long way short of what it should be and it cost him three shots in his first two holes and, courtesy of a tee shot out of bounds at the 17th, three more at the penultimate hole.

“I didn’t hit the driver very good today. I was trying to be bolder, more aggressive,” said Woods, who famously used his driver once in four rounds on his way to victory eight years ago.

“With the wind the way it was I could take some of the bunkers out of play, get it down there where I could hit a sand wedge into the greens even from the rough.

“Angel (Cabrera, one of his playing partners) was doing that yesterday and did it quite effectively with a different wind but this was a more difficult wind.

“I figured today was a chance where I could go out and be aggressive but I just didn’t drive the ball.”