Even though they unloaded more shots at goal, stretched their opponents all over the pitch, and never gave up fighting, the dream finish evaded Gerry Davis's side which was made up of players from Connacht-Munster.
The outstanding run of seven competitive games, four wins, eight goals scored, and two goals conceded helps to mark this team out as one of the most talented and hard-working of all the amateur sides to pull on an Irish jersey.
Having won on the competition on home soil two years ago there was hope that the Irish outfit could bring the trophy home again. But it wasn't to be as Zagreb got their revenge from 2015 by claiming victory.
A single goal from Toni Adzic on 26 minutes separated the sides at the interval and Davis's men couldn't find a way back despite rattling the woodwork and forcing the opposing goalkeeper to pull off four big saves.
This is the second time that an Irish side has finished as runners-up in this competition and Davis, his players and the support staff should be commended for achieving what they have.
The game was a tight affair with no major saves early on. Željko Štulec had the game’s first attempt at goal in the 11th minute for Zagreb then Nikica Brujić also failed to hit the target in the next few minutes.
Shane Daly-Butz had Ireland’s first chance in the 21st minute but failed to trouble the Croatian keeper.
The decisive moment of the game came five minutes later when Adžić turned the ball home to break the deadlock.
David Stack and Stephen Kelly came close as the half drew to a close before Soldo and Štulec both had shots in the Irish defence blocked. The same fate happened to Ćibarić two minutes before the break.
Eoin Hayes was denied an equaliser by a defensive block in first half injury-time.
Davis’s side pushed hard to equalise in the second half with David Stack denied by Zagreb keeper Nikola Durdek three minutes after the restart then the keeper kept out an effort from Kevin O’Connell in the 54th minute.
Eugene O’Donovan was off target with an effort from a Stack corner on the hour then the keeper kept out an effort from Stack three minutes later.
As the game entered the final ten minutes the Irish pushed hard to level with Daly-Butz denied by a defensive block then in injury-time the UCC attacker was so close to snatching a brilliant leveller with a long range drive that smacked the Croatian crossbar.
Five minutes into injury-time Irish defender Mark Horgan was denied a dramatic equaliser by Durdek and moments later the final whistle blew on a fantastic campaign for Davis, his staff and players.
“It was another game where the conditions weren’t with us. We struggled with the heat - one player had double-vision and another player suffered nausea so it was very tough,” said Davis.
“In the second half it got slightly cooler and we pressed them hard. We hit the crossbar and fired a great effort across goal. How we didn’t find the equaliser I’ll never know.
“Unfortunately it wasn’t meant to be. If the game had started later in the day we’d have won it. No doubt.
“Overall I’m very proud of the work that was put in and what we’ve achieved. We’ve won a European medal. There are very few Irish footballers with medals from a European competition.
“People around the country are so proud of what this team has done. We’ve made a stir over here. UEFA and the Turkish FA were very complimentary of what we did.
“It’s just one defeat in 16 Regions Cup games. Today was only second goal we conceded in seven games. It’s been a remarkable run with a lot of work put in for the past number of years.”
Zagreb: Durdek; Mohac, Vrbat, Ivkovic, Mislimi; Cibaric, Lihic, Brujic (Krznar 87); Adzic (Svigir 74), Soldo (Filipovic 61), Stulec.
Region 2: B O'Connell; Hoey, Kelly, Horgan, Higgins; Carr, Stack (Chris 77), O'Donovan, Daly-Butz; K O'Connell (Hoban 71), Hayes.
Referee: Artyom Kuchin (KAZ).