Home favourite Rory McIlroy produced a late birdie burst to make the ideal start to his bid for a second Amgen Irish Open title.
McIlroy - making his return to DP World Tour action - mixed six birdies with three bogeys during a three-under 68 at Royal County Down, a 12-shot improvement on his first round the last time the event was held at the venue in 2015.
The world No 3 took advantage of the par-five first and then cancelled out a three-putt bogey at the par-four fourth by holing from 18 feet at the eighth and getting up and down from off the green to birdie the par-five 12th.
McIlroy was in danger of letting a promising round slip away when he bogeyed the 14th and 15th to fall back to level par, but he birdied each of the last three holes to stay within two strokes of early lead Todd Clements.
"Any time you can shoot three under around this place you have to be happy," McIlroy said. "The conditions were pretty tough early on and then the wind seemed to settle a little bit those last few holes and it was nice to take advantage of that and play them the way I did.
"Giving those shots away on 14 and 15, to get more than both of them back on the last three holes was a great way to finish and gives me plenty of momentum going into Friday morning. It's nice to get off to a good start [in Northern Ireland] for a change!"
Clements, beginning on the back nine, birdied two of his opening three holes and added a 20-foot eagle at the 18th to reach the turn in 32, then moved top of the leaderboard with a close-range birdie at the par-five first.
The Englishman dropped shots at the second and fourth to slip back to three under, only to go millimetres away from a hole-in-one at the par-three seventh and post back-to-back birdies to card an opening-round 66.
Sami Valimaki and Alejandro Del Ray share second on four under, with McIlroy in tied-fourth with Will Enefer, Marcus Armitage, Filippo Celli and Thriston Lawrence - the player closest to him in the Race to Dubai standings.
Veteran Soren Kjeldsen rolled back the years with a two-under 69, while Robert MacIntyre carded a level-par 71 and Shane Lowry recovered from a slow start to card a one-over 72.
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"Starting five, five, five wasn't ideal and then where I hit it on the fourth obviously wasn't ideal either," Lowry said. "That up and down kind of gave me a bit of a kick start that I needed and a bit of a pep in my step.
"You look at the scoring out there, there's nobody shooting really low. Even in major championships, people always shoot good scores on the first day. So you can tell how hard of a test that is."
Who will win the Amgen Irish Open? Watch throughout the week live on Sky Sports. Live coverage of the second round begins on Friday from 8am on Sky Sports Golf and Sky Sports+, with a second session the live from 4pm on Sky Sports Mix. Stream the Irish Open, Solheim Cup and more with NOW.
