Colin O’Brien’s side created numerous chances but could not convert them and were ultimately undone by a last gasp Turkish winner.
Tyriek Wright had the game’s first chance in the fourth minute but he shot over after connecting with a Sean Brennan shot which was off target.
Sean Mahon Brennan troubled the Turkish defence on the counter in the ninth minute but his dangerous ball across goal was knocked to safety.
Harry Clarke made his first save of note in the 17th minute when he denied the home side in a one versus one situation.
Sean Brennan played through Ciaran Brennan in the 28th minute but keeper Canberk Yurdakul made an important save.
In the 32nd minute Turkey had a big chance when an effort from Firat Gullu was blocked by Oisin McEntee before hitting an Irish upright.
Ciaran Brennan was denied by the keeper diving at his feet in the final minute of the first half then in the 50th minute he had a shot narrowly over.
McEntee made another important intervention to deny Turkish striker Ali Yavuz Kol in the 61st minute before the same attacker had another attempt blocked by Irish defender Jamine Nwanze.
Adam Idah had a chance saved comfortably in the 71st minute then Irish keeper Harry Clarke had to make a reaction save after a 79th minute corner.
The winner came 60 seconds later when a contentious free-kick was fired in an struck the crossbar before being eventually turned in by Bora Ulu.
Ireland will meet Austria in their final game in the tournament on Saturday. The Netherlands beats Austria 4-0 in the other game today.
"It was again very positive. We'd the best chances in the game and were dominant for periods which was very pleasing. Unfortunately Turkey scored right at the end which was hard on our players," said O'Brien.
"The big lessons again were about finishing our good chances and the boys suffered a cruel blow with the concession of the late goal and will be a bit down but they should look back on a good performance and bounce back in the final game on Saturday.
"The boys came off the pitch today knowing they were the better side for long periods and that's hugely positive. The players who didn't start Tuesday all started today which was very important. Again the match was played in testing conditions and Turkey were also not afraid to go direct if they had to so gave us a different type of challenge to the Netherlands."
REPUBLIC OF IRELAND: Harry Clarke, Jamine Nwanze, Sean Brennan, Sean Mahon Brennan, Kevin O'Reilly, Adam O'Reilly, Kameron Ledwidge, Jack Kelly, Tyriek Wright, Ciaran Brennan, Oisin McEntee. Subs: Adam Idah for Ciaran Brennan 60 mins; Callum Thompson for Kelly 60.
FIXTURES & RESULTS
U15 International Tournament
Tuesday, February 2
Republic of Ireland 1-2 Netherlands
Turkey 3-0 Austria
Thursday, February 4
Republic of Ireland 0-1 Turkey
Netherlands 4-0 Austria
Saturday, February 6
Republic of Ireland v Austria, Emirhan Sports Complex, Turkey (12:30apm Irish)
Turkey v Netherlands, Emirhan Sports Complex, Turkey (10:00am Irish)