Rory McIlroy of Northern Ireland tees off on the 18th hole during Day One of The 150th Open at St Andrews Old Course on July 14, 2022 in St Andrews, Scotland. (Photo by Stuart Kerr/R&A/R&A via Getty Images)

They say a good start is half the work but Rory McIlroy knows he must back up his sensational six-under 66 today if he’s to end his eight-year Major drought at St Andrews.

While he’s now 12-under par for the opening rounds of the Majors this year compared to 34-over during his barren streak between 2015 and 2021, his goal now is to continue going forward on a hard and fast Old Course he described as “the fiddliest” he’s ever played in an Open.

“I need to go out tomorrow and back up what I just did today,” said the Co Down man (33), who is two strokes behind PGA Tour rookie Cameron Young, who carded a bogey-free, eight-under 64 for the lowest career debut round at The Open in the modern era. “I think that's important to do.

“I’ve seen the golf course now in tournament play and tournament conditions and know what to expect. Tomorrow's an important round, just to go out and back up what I've done today.”

The Old Course is slippier than an Olympic skating rink but while the R&A tucked the pins near the edges of slopes, a three-under 69 left Pádraig Harrington inside the top 25.

“It's the fiddliest Open that I've played,” McIlroy said. “It's the only way I can really describe it. It's just really fiddly out there. Carnoustie was firm in 2018, but it wasn't like this.

“I think as the tournament progresses, you're going to get some funny bounces and it's going to test your patience at times. And fiddly hasn't really been my forte over the years, but I'm hopefully going to make it my forte this week.”

Shane Lowry and Séamus Power certainly didn’t find it easy as they discovered gorse and bunkers that led to them momentum-sapping double bogey sixes en route to respective rounds of 72 and 73.

But McIlroy’s only bogey of the day came at the 13th, where he left himself a 90 footer for par after twice flirting with the front bunker.

If you can pull off the shots on the driveable par fours and reachable par-fives, there are five or six “easy” birdies to be made.

McIlroy did just that, rolling in a 55 footer at the first before knocking in birdie putts at the fifth (two-and-a-half feet), sixth (7-feet) and seventh (8-feet) to turn in 32.

He then two-putted the driveable 12th to go five-under and followed that bogey at the 13th with a pitch and putt birdie at the 615-yard 14th, which he reduced to a 379-yard drive, a 220 yard wedge over the green and a lovely pitch to three feet.

The finishing holes were tricky but he negotiated the last four in one-under par as he followed a chip and putt par at the 17th with a two-putt birdie from 85 feet at the last.

“Yeah, fantastic start,” said the Co Down man, who didn’t have a three-putt in his lowest opening round at The Open since he shot 66 en route to his first Claret Jug at Hoylake in 2014. “Just sort of what you hope will happen when you're starting off your week. I mean I did everything that you're supposed to do around St Andrews.

“I birdied the holes that are birdieable and I made pars at the holes where you're sort of looking to make a par and move to the next tee. And didn't really put myself out of position too much.

“So, yeah, overall really pleased. It's another good start at a major. Three in a row for me now. And looking forward to the next few days.”

World number 32 Young (25) was a college team mate of The Island’s Paul McBride at Wake Forest and hardly put a foot wrong as he found all 18 of the mostly huge greens.

“I think we worked our way around the golf course really well,” said the New Yorker, who has had four top-three finishes this year, including a tie for third in the US PGA. “I don't think that I played a perfect round of golf. I think it just scored really well. And I think we thought our way around kind of the way you have to out there.”

Australian Cameron Smith was third on five-under after carding a beautiful 67 alongside Power.

As Tiger Woods double-bogeyed the first and struggled to a 78, a host of big names are lurking on four-under after 68s alongside amateur Barclay Brown including Lee Westwood, Viktor Hovland, Dustin Johnson, and world number one Scottie Scheffler.

"There's a few holes where I don't know if it's possible to even hit the fairway, like if you're going to take the bunkers out of play, you can't hit the fairway,” the Masters champion said. “So we're kind of just trying to manage our way around the golf course and play into certain spots.”

Struggling with a knee injury, Harrington found the last few holes and felt deflated after missing a three footer at the 16th and somehow followed a brilliant par-save at the 17th with a closing birdie for a 69.

“I’m shattered,” said Harrington. “When I missed the putt on 16, I couldn’t see a way back to the clubhouse. It was a long way home those last two holes but I am very happy with how I played.”