Ireland captain Andy Balbirnie lamented a poor spell with the bat as Ireland slumped to a six-wicket defeat to England at Southampton.
The hosts won the toss and elected to put Ireland in to bat first at the Ageas Bowl.
Things started poorly for Ireland when opener Paul Stirling went for 2 with the fourth ball of the first over.
It would be the first of five wickets for David Willey, who was awarded man of the match.
Balbirnie, debutant Harry Tector, Gareth Delaney and Lorcan Tucker would all follow Stirling to the pavilion before they reached the 7th over of their innings.
The captain told Sky Sports that those early wickets cost Ireland dear, "Very disappointing," is how he viewed the start.
"We didn't assess conditions early enough, had a bad 5-6 overs and we can't afford that.
"Our training has been good but you can't replicate matches and maybe there was some rust.
"[We] need to be able to assess conditions better. They bowled well up front, but Curtis Campher was very good, he dug in and got a decent score."
Something for Ireland fans to shout about! Andy McBrine slog-sweeps Moeen Ali handsomely for six over deep midwicket.
Ireland 1⃣2⃣4⃣-7⃣ after 35 overs...
📺 Watch #ENGvIRE ODI 👉 https://t.co/EgKn7so5qV
📰 Over-by-over blog 👉 https://t.co/WzhQDIArCL pic.twitter.com/lRwNoeFJQC
— Sky Sports Cricket (@SkyCricket) July 30, 2020
Indeed it was Campher's debut knock of 59 that added an air of respectability to the visitors' innings.
He put on partnerships of 51 and 66 with Kevin O'Brien and Andy McBrine respectively before Ireland were eventually bowled out for 172.
Ireland gave their hosts something to think about when Jonny Bairstow fell for just 2 inside 3 overs.
But in reality, England were troubled little by Ireland's attack - reaching their target with 133 balls remaining of their innings.
Balbirnie says changes are unlikely for the second meeting of the sides on Saturday, "The guys that have gone out today need a chance to redeem themselves, not a lot of technical stuff you can do but just get back out."
His opposite number Eoin Morgan was delighted with the "outstanding" display of Willey with the ball, "Where he's been in the last year or so, missing out on the World Cup, it's a fantastic story and comeback.
"Delighted to have him back and firing. He and Saqib [Mahmood 2-36] were outstanding, they really did peg Ireland back."