Portrush - Home favourite Rory McIlroy and Tiger Woods both endured dreadful starts to the Open Championship on Thursday, while American JB Holmes claimed the lead as the championship returned to Royal Portrush for the first time since 1951.
LEADERBOARD: 148th Open Championship - Round 1
Organisers the R&A are anticipating the second-biggest ever Open attendance, with 237 750 people expected to come through the gates this week in Northern Ireland, but spectators were left stunned by McIlroy's immediate collapse.
He briefly battled back after a bogey at the par-three third hole, but missed a tiny putt to double-bogey the 16th, tripled-bogeyed the last and eventually carded a disastrous eight-over 79.
"I guess when you play your first and last holes in a combined seven over par you are starting on the back foot," said McIlroy.
The four-time major champion, who fired a course-record 61 at Portrush at the age of just 16 in 2005, was given a huge reception on the first tee as the crowds huddled around the opening hole for a sight of the local hero.
But he quadrupled-bogeyed the first after hitting his tee shot out of bounds.
Woods saw his bid for a 16th major title all but come to a premature end as he stuttered to a miserable seven-over 78, including six bogeys and a double bogey at the par-three sixth.
The Masters champion's sole birdie of the day came at the par-four 15th, which he celebrated with an ironic raise of his arms, but he fittingly finished his round with one last bogey.
Woods and McIlroy now face daunting tasks to try and make the cut.
McIlroy is already 13 strokes adrift of leader Holmes - with Woods one better off - after the 37-year-old birdied the 18th to post an excellent five-under 66 and move one shot clear of previous leader Shane Lowry.
Holmes' previous best major finish was third at the 2016 Open and he has missed eight cuts in his last 13 events, and withdrew from one of the others.
Ireland's Lowry held the lead for much of the day before being toppled by Holmes, having to settle for second place heading into Friday.
The world No 33, who made five birdies in his 67, admitted he struggled to keep his nerves in check on the first tee, with the crowds lending strong support to all six players from the Republic of Ireland and Northern Ireland.
"It's the Open, it's in Ireland. I feel like I'm hitting it well. Of course I feel uneasy," he said.
There is a group of 13 players in the clubhouse just two strokes off the lead on three-under, including world number one Brooks Koepka and Spaniard Jon Rahm.
American Koepka made his only bogey of the day on the penultimate green, but felt he could have done much better.
"Didn't really make any putts. Didn't take advantage of anything to really go low," said Koepka, who has finished in the top two of all three majors this year and is looking to add the Claret Jug to his two US Opens and two PGA Championship titles.
"But definitely didn't shoot myself out of it, so I'm okay with that."
Rahm, who won his second Irish Open title at Lahinch two weeks ago, held the lead on his own on various occasions, but dropped back with bogeys at the 15th and 18th holes.
English pair Tommy Fleetwood and Lee Westwood are also among those on three-under, with the latter still looking for his maiden major title in his 25th consecutive Open appearance.
Ryan Fox of New Zealand had a record-breaking day with the lowest back nine in Open history as he came home in 29 to get to join the pack of players who signed for 68s.
Reigning champion Francesco Molinari saw his hopes of becoming the first man to defend the title since Padraig Harrington in 2008 take a blow, only managing a three-over 74.
Argentina's Emiliano Grillo got the crowds excited with the first hole-in-one at the championship since 2016 on the par-three 13th.