Rory McIlroy sensationally came back from the dead and declared: I'm not out of this Open.

The Holywood star, 28, looked like an also ran when he crashed to five over par after six holes in perfect conditions at Royal Birkdale.

But reminded who he was by caddie JP Fitzgerald — "He said, 'You're Rory McIlroy, what the f**k are you doing?'"— he made a miraculous par-save from 20 feet at the eighth, then stormed home in four under 32 for a one-over 71 that felt almost as good as the 65s that gave Jordan Spieth, Brooks Koepka and Matt Kuchar the first round lead.

It was a remarkable turnaround from a player who has been out of sorts since he suffered a stress fracture of the ribs in South Africa in January and just missed three of his last four cuts.

And he confessed that he was totally lacking in self-confidence from the start as he bogeyed the first, then dropped four more shots in a row from the third before birdies at the 11th, 15th, 17th and 18th revived his chances of a fifth Major win.

Admitting he feared his Open was over before it began, he said: "Those thoughts ran through my mind. I was thinking, geez, here we go again.

"But I just needed to stay patient and stay with it. I didn't get angry out there at all. I didn't let my head drop too much.

"So I kept a good, positive attitude. And it turned around for me, thankfully. It was nice to see the putt on 18 go in and close out today with something really positive."

Fitzgerald's pep talk didn't work straight away as McIlroy bogeyed the sixth and turned in five over 39.

"I really didn't find the middle of the clubface until the seventh tee but I hit a good tee shot on seven, even though it didn't hit the green," McIlroy said. "It was a better strike, a better golf shot.

"I took a little bit from that and I'll just go to bed tonight thinking of those last 12 holes and try and emulate that."

McIlroy started by firing his approach under a bush, then chipped over the green, fluffed a chip and had to hole a 20 footer from off the green for a bogey.

He then failed to get up and down for par at third, dropped another shot after bunkering his tee shot at the short fourth and three-putted the fifth to slip to four over.

Another shot went at the sixth where he came up short of the green from the rough.

Rory McIlroy in action in round one of The Open at Royal Birkdale

But after making a good par a seventh, it all turned around at the eighth, where he missed the fairway miles to the left, hacked his recovery into more deep rough but then hit a 95-yard approach to 20 feet and made the putt for par.

A tap in birdie from inside four feet at the 11th got him back to four over and he then two putted for birdies at the par-five 15th and 17th before rolling in an 18 footer for another at the 18th.

It reminded McIlroy of how his Ryder Cup fourball partner Ian Poulter birdied four of the last five holes on the Saturday to set up Europe's incredible 2012 Ryder Cup comeback at Medinah.

"I could be standing here having hit 18 greens and shot one-over and missed every putt and feel terrible," McIlroy said.

"But because of the way I started, I actually feel really positive. It's a bit like Ryder Cup at Medinah in '12.

"We're 10-6 down on Saturday night but we feel like we were right in with a chance, because we won the last two points.

"It's sort of like that. Even though there's a lot of golf left, in other circumstances it might have been a disappointing day. But just with the way I finished, I feel really good about it.

"With the weather we're expecting tomorrow, I still feel I'm in the golf tournament.

"If I can go out and play a good quality round of golf in the morning and try to get in the clubhouse somewhere around even par, under par, I'll still be around for the weekend."

As for his lack of belief, McIlroy said it was simple lack of confidnce but he'd try to banish those thoughts and back up his comeback round today.

"A bit of a lack of confidence just over the last couple of weeks was just letting that get in my head a little bit," he said.

"It's a major championship. These are the four biggest tournaments of the year. And you want to go out there and shoot a good score and get off to a good start.

"I'm always more nervous playing in these four tournaments than I am anything else. And I felt that out there today it was just because of the lack-of-self belief I had going out.

"But somehow I was able to find it halfway through the round and, again, that's what I'm going to concentrate on going into tomorrow.

"I'm really happy with what I've done this afternoon after the start. If I go out tomorrow under bad conditions and shoot something in the 60s, I feel like I'll be right there for the weekend."

Can he win the Open from here?

"I hope so," he said. "I was four-over through three holes last year in Boston and won that tournament. So I've done it before."