Cameron Young leads The Open as Woods struggles
There had been worries in the run up to the season's final major that calm winds and firm, fast conditions would leave the venerable Old Course vulnerable to low scoring and that's exactly what happened as the world's best golfers attacked the defenceless layout.
But not everyone was feeling at home during a grinding day on the Scottish links, including Tiger Woods (46), who on Wednesday was made an honorary member of the Royal and Ancient.
Twice a winner at St Andrews, Woods never got in gear on a course he calls his favourite in the world and laboured to a six-over 78 which left him in danger of missing the cut.
Still chasing a maiden PGA Tour title, Young showed the 'Grand Old Lady' no respect as he challenged the major championship record score of 62 set by Branden Grace at Royal Birkdale in 2017, returning a clean card sprinkled with eight birdies.
"I'm happy I shot 64," said Young when questioned about his lack of excitement. "I'm happy that, as far as I know, I'm still leading The Open Championship, but it's not going to change how I feel an hour from now."
With two titles this season and top 10 finishes in all three majors including a runner-up result at the Masters, McIlroy arrived in St Andrews as the man to beat and a six-under 66 will have done nothing to convince anyone to switch their bets.
The Northern Irishman got his day off to a flying start, rolling in a 55-footer for birdie at the first.
He continued to build momentum by stringing together three straight birdies from the fifth before heading into turn, where he picked up three more and his only bogey of the day.
"Fantastic start," gushed the four-time major winner. "Just sort of what you hope will happen when you're starting off your week."
Young, who last month had held a share of the first-round lead at the Memorial Tournament before finishing in a tie for 60th, will not feel like he has much breathing room with challengers lining up behind him.
Australian Cameron Smith (28), winner of golf's unofficial fifth major the Players Championship and Englishman Robert Dinwiddie (39) returned 67s to sit three back.
Lurking four off the pace on 68 is a pack of eight that includes Masters champion and world number one Scottie Scheffler (26) and British amateur Barclay Brown (21).
Some of the most prominent players who have been recruited by the controversial Saudi-backed LIV Golf Invitational Series featured on the leaderboard on Thursday. The breakaway series has split the sport after poaching players from the PGA and DP Tours.
LIV members and former world number ones Dustin Johnson (38) and Lee Westwood (49) along with Taylor Gooch (30) were in the hunt with 68s.
Collin Morikawa (25) got is Open title defence off to a bumpy start, mixing four birdies with the same number of bogeys for a level par 72.
But no one struggled more than Woods, who got his day off to a horrific start when his second shot bounced into the creek guarding the first green leading to a double-bogey.
Playing just his third event since a 2021 car crash nearly resulted in the loss of his right leg, Woods never found his comfort zone as he added two more bogeys and double to go six-over after just seven holes.
As ever the 46-year-old refused to wave the white flag, hitting back with back-to-back birdies at nine and 10 but the magic would not last.
That did not stop a crowd from gathering around the final hole in the Scottish twilight as bagpipes played in the distance. The fans cheered wildly as the 15-time major winner appeared on the green.
"I'm going to have to shoot 66 tomorrow to have a chance," said Woods. "Obviously it has been done.
"Guys did it today and that's my responsibility tomorrow to go ahead and do it."