So much for a happy homecoming. The rocky relationship between Rory McIlroy and the Irish Open shows no sign of easing. Even the hosting of this event by McIlroy’s charity, it seems, is not sufficient to improve the struggles the world No1 has with his native event.

McIlroy has missed the Irish Open cut twice in succession. The odds are in favour of an unwanted hat-trick after the 26-year-old stumbled to an opening round of 80 at Royal County Down. This was akin to throwing a house party during which guests take it upon themselves to trash the property. This marked McIlroy’s worst round in Europe since another 80 at the 2010 Open Championship but somehow, given the environment, it felt like the more painful.

McIlroy failed to make a single birdie, with the sight of him propping up the field as he completed media duties a curious one to say the least. He was at least spared that fate by the end of play on Thursday. During them, McIlroy was rueful rather than angry. He seemed slightly embarrassed to be the recipient of sympathy for galleries who flocked to Newcastle in expectation of another narrative entirely.

“Nothing went right,” McIlroy conceded. “It’s my fifth week in a row, and I’m not saying I felt flat out there, but trying to muster something up to get myself going and get some sort of momentum was sort of difficult.

“You know what to expect when you come to an Irish Open and I’ve said for the last couple of years I want to try and embrace it and relish the fact that you’re here and everyone wants to see you do well. So you should be able to use that to your advantage. I just haven’t been able to do that as of yet.”

Even taking tournament context into account, this was a bizarre capitulation from one so talented. Further bad news derives from the fact this, surely, is not the kind of course you can zip round in 64 to haul yourself back from the precipice.

“I want to at least go out there tomorrow and fight for it, try and claw my way back up towards the cut line,” McIlroy insisted. “And if I can sneak in there, that’ll be great.”

The only hints towards this Thursday scenario could be found in the backdrop. McIlroy’s commitment to the Irish Open has placed considerable demands on his pre-tournament time. A cold, routinely rain-soaked morning beneath the mountains of Mourne also hardly played into McIlroy’s hands but, to his credit, he refused to cite conditions as an excuse. Perhaps the burden of responsibility in front of such a captive audience plays more heavily on the four-times major winner’s mind than he cares to admit.

It was ragged play – tee shots aside – that contributed to this eye-catching score. McIlroy’s confidence was jolted by a series of wayward irons and missed, short putts early in his round, which triggered a second plus-40 nine-hole run in a row. On that back nine, McIlroy’s first half, six putts from 6ft or less failed to find the bottom of the hole.

From there? Things barely improved. McIlroy’s last two competitive rounds have featured 158 shots, immediately following a runaway and record success in North Carolina. Proof, if needed, of what an impossible sport this can be to properly predict. “It was pretty good off the tee, it just got worse as I got closer to the green,” McIlroy added. “I want to go out there and play well, not just for myself but for a lot of other people.

“I’m not sure what I’m going to need to make it into the weekend, but obviously I would love to be here for that.

“I really put myself behind the eight ball today because the back nine is the more scorable nine here. To go out there and shoot five over on that nine, I couldn’t really do much on the front nine because it was playing so tough.”

Rickie Fowler, who partnered McIlroy, reached two under par after as many holes but found things slightly tougher thereafter. Yet he will be content to have emerged unscathed after signing for a level-par 71.

“It’s tough to see,” the American said of McIlroy’s toils. “You don’t want to see someone struggle and it’s not the start that he was looking for this week. I’m assuming that it’ll be a little different day tomorrow for him. That’s golf. We’ve all been through it, and I’m sure we’ll go out and have some fun, hopefully feed off of each other tomorrow.”

Martin Kaymer, the third member of this marquee group, found things similarly tough; the US Open champion could fare no better than 79.

Before the tournament began, McIlroy and Fowler were understandably hailed as returning competitors from the 2007 Walker Cup, which was held at County Down. What may have been lost in the melee was that Danny Willett, then a 19-year-old, also featured eight years ago.

Willett duly offered a reminder. His opening round of 69, two under par, put him two shots off the lead and maintained what has been a highly impressive start to 2015. Just behind, Luke Donald’s 70 was timely with his continuing quest to earn a US Open place in mind.

Padraig Harrington and the German Maximilian Kieffer hold the lead on four under par, one shot clear of Denmark’s Soren Hansen.