Mehmet Topal's sweetly-struck volley condemned a new-look Republic of Ireland to friendly defeat in Turkey as Martin O'Neill's new boys were given a lesson in international football.
O'Neill handed senior debuts to Declan Rice, Scott Hogan and substitute Matt Doherty and first starts to Alan Browne and Sean Maguire in Antalya, but it was Fenerbahce midfielder Topal who ultimately won the day with a 52nd-minute strike to clinch a 1-0 win.
With the Republic trialling a 3-5-2 system, they were largely overrun in central midfield to leave Hogan, Maguire and later Shane Long starved of meaningful possession.
However, there were positives with Rice turning in an assured performance on the left side of the defensive trio and later in midfield, and skipper Seamus Coleman getting 62 minutes under his belt a day short of a year since he suffered a horrific double leg fracture on international duty.
The Irish squad will reassemble in May for friendlies against France and the United States, and it remains to be seen which of O'Neill's understudies have done enough to warrant another call-up once his rested and injured senior players return.
Coleman and James McClean were asked to operate as wing-backs, but found themselves defending rather than attacking in the early stages as full-backs Hasan Ali Kaldirim and Gokhan Gonul pinned them inside their own half and Hakan Calhanoglu and Yusuf Yazici dictated the tempo behind lone striker Cenk Tosun.
Calhanoglu and skipper Topal both sent long-range efforts high and wide as keeper Colin Doyle, winning his second Ireland cap 10 years and 304 days after his first, was largely untroubled despite the pressure.
Indeed, the visitors might have taken an 18th-minute lead when Hogan ran on to Jeff Hendrick's pass and rounded keeper Volkan Babacan, only to fire into the side-netting as the angle narrowed prohibitively.
The home side's response was concerted and Doyle had to get down to parry Tosun's well-struck 28th-minute shot, although he could only look on in hope seconds later when central defender Shane Duffy got his head to Gonul's driven cross and almost diverted it into his own net.
However, despite the Turks enjoying the better of the game, half-time arrived with the deadlock unbroken.
They needed just seven minutes of the second half to force their way in front when Calhanoglu and Yazici worked a short corner and the latter crossed for Topal to volley home expertly from close range.
Maguire and McClean started to come to the fore as the Republic finally made their presence felt, although Doyle needed two attempts to claim Calhanoglu's skidding 67th-minute effort with Turkey still in the driving seat.
O'Neill shuffled his pack as the game passed the hour-mark, in the process handing McClean a more accustomed midfield role, and he almost made an impact with 15 minutes remaining when he broke free down the left and fired in a dangerous cross which was thumped away by Okay Yokuslu.
Substitute Daryl Horgan curled an 85th-minute effort well wide with Ireland finishing on the front foot, but it was a case of too little, too late.