One of the sweetest sounds in sport is the elongated swoosh of Rory McIlroy’s driver connecting with the ball - more yogic exhale than violent clank. But on Friday at the 414-yard par-four 9th, McIlroy was still searching for inner peace at one over for the tournament, watching the leaderboard turn a sea of red. So out came the big dog. The gallery murmured, McIlroy fired, and the ball compressed through the air at 190mph, flying 403 yards onto the green, 11 feet from the hole.

"Honestly, my gameplan was to hit it to the top of the hill and hit a wedge on," he said. "But sometimes opportunities present themselves and you have to take them." Alas, he couldn't follow his own prescription: the eagle putt was tentative, and he walked off with birdie. It was his round in microcosm: imperious driving, so-so irons, and missed birdie chances from 10 to 20 feet, leaving him to settle for a 67 - three under - while Lucas Herbert and Sam Burns hit record-equalling 62s.

"The main objective was to be here for the weekend," McIlroy said. "I felt like I left a couple out there. Then you look at the board and see a couple of 62s, and you feel like you could have done a bit better." At one under going into day three, he hasn't discounted his chances, noting that apart from Cam Young and Burns, few atop the leaderboard are comfortable breathing the dizzy air of a major on moving day.

"There's a couple of guys up there, this will be their first experience of playing in the lead at a major championship on the weekend," he said. "If I can get off to a decent start tomorrow, be four or five under, I'll be right in it." His putting improved from day one - when he ranked 155th out of 156 in strokes gained, losing three strokes to the field - but he remains uncomfortable with Birkdale's quirky greens. He sought help from putting guru Brad Faxon before the second round, but admits there's work to do.

"I'm still trying to figure out these greens a little bit," he said. "I hit a couple of putts yesterday, felt like I hit good putts, and they did something completely different to what I saw in the read - that's a little unnerving." Meanwhile, playing partner Matt Fitzpatrick missed the cut at four over, lamenting the randomness of links golf: "I've hit three shots exactly how I wanted them. One is in a bush 30 yards long. One dropped off the green after 15 seconds. That's the way links golf is." Perhaps that randomness gives McIlroy an opportunity - if his driver keeps firing, and the rest of his game starts to sing too.