Shane Lowry shot a 67 as he made a fine start to the Open Championship in Portrush, while former winner Darren Clarke and Amateur champion James Sugrue have opened with level par rounds
Lowry made five birdies and rued some missed opportunities in his back nine, albeit also having to scramble to save par in his final two holes.
The only bogey of the day was on the 11th as he picked up shots at nine, 10 and 12 in an eventful four holes.
It was enough for the clubhouse lead on four-under at lunchtime.
Lowry got a few things off his chest in a pub pep talk with his coach on the eve of the Open and that allowed him to turn up the next day and set the clubhouse lead.
The Offaly man felt he had a few issues with his game having practised around Royal Portrush this week so headed down to the nearby Bushmills Inn with coach Neil Manchip to thrash a few things out.
Whatever was said clearly did the trick as despite admitting he still felt uneasy as he arrived at the first tee on Thursday morning he walked off the 18th green to sign for a four-under 67.
"I don't feel like practice went unbelievably well this week. I felt a little bit uncomfortable," he said.
"We went for a coffee yesterday down at the Bushmills Inn and we found a little quiet room, we had a great chat for about 40 minutes.
"We just put everything out in the open, everything out on the table, what could happen, what might happen.
"I left that room full of confidence and ready to go. (But) I was probably as nervous as I've been in quite a while on the first tee, almost ever, I'd say.
"It's the British Open, it's in Ireland, I'm playing well, I feel like I should come up and do well.
"I'm sure there's plenty of golfers standing on the first tee feeling uneasy. You wouldn't be human if you weren't nervous or uneasy about playing in the biggest tournament in the world.
"I just hope I'm nervous on Sunday afternoon out there. It's right where you want to be, and you have to tell yourself that when you're there.
"Where would you rather be? Would you rather be here or sitting at home watching on TV?"
The 2011 winner Clarke was given the honour of hitting the opening tee shot at 6.35am at Royal Portrush and holed a 15-foot birdie putt at the first.
He carded four more birdies - at the third, fifth, 12th and 15th - to go with bogeys at six, 11, 14, 16 and 17, to card a 71.
With early-morning sunshine piercing the cloudy skies Clarke, who owns a house overlooking the course, was welcomed on the first tee to huge cheers.
The 50-year-old has missed the cut in three of the last four years but, after sharing a few words with victorious Ryder Cup captain Thomas Bjorn, he got off to a confidence-boosting start by finding the fairway in breezy conditions.
More cheers accompanied his departure from the tee box with Clarke relaxed enough to stop to briefly chat to fellow former Ryder Cup captain Paul McGinley who was broadcasting live close by.
Clarke has tapped home countless birdies on Royal Portrush's 'White Rocks' par three, but never before to step ahead of the pack in an Open Championship.
"I didn't think I would feel the way I did, but the support, the crowd, everything about it, I just thought 'wow, it's The Open Championship'," said a tearful Clarke, who finished with an admirable level par.
"This was really special; the last time I had people shouting like that was 2011 on the 72nd hole, so it was fabulous.
"The Open being here isn't about us, it's about how far our country has moved forward, it's about the economic benefits that the legacy will bring.
"Look back 20 years and we wouldn't have been having this conversation.
"Maybe not up here, but you'd have seen police everywhere on the street.
"The stands are full, you can't get a ticket.
"Hopefully the people who make decisions for big sporting events can take a look at this and look upon us favourably here in Northern Ireland and Ireland."
Sugrue carded a 71 also, with four birdies and four bogeys during a remarkably composed round from the 22-year-old Mallow man, who won the Amateur Championship at Portmarnock last month.
Padraig Harrington disappointed with a four-over 75. Graeme McDowell threatened to get involved after reaching three-under through 11 but two bogeys and a treble at the last saw all the good work ruined.
He finished on two-over.
Rory McIloy endured a nightmare start with a quadruple bogey on the first and despite a revival, he carded a 78, eight-over.