Arsenal's Under19-side discovered just how hard it is to play abroad as they were beaten 2-0 by Olympiacos in Athens on Wednesday night.
Competing in the NextGen competition for the first team, Arsenal had made the perfect start when they defeated Marseille 3-0 last month and there were high hopes that a similar result could be achieved in Greece.
The competition gives the youngsters a chance to see what it would be like to play in the Champions League as they had to play in difficult conditions on a warm evening which tested the player's fitness.
Arsenal coped well for much of the game, but two late goals condemned Terry Burton's side to a first defeat, with right-back Hector Bellerin also being handed a late red card.
The first goal came just six minutes from time as midfielder Rafail Soukias slotted home after an excellent save from Reice Charles-Cook.
As Arsenal went in search of a late equaliser, Bellerin was forced to bring down Nikos Ioannidis who was through on goal and the defender was shown a red card.
From the resulting free-kick Leandro Climaco Pinto curled the ball past a helpless Charles-Cook to hand the victory to Olympiacos.
Chances were few and far between in a tight first half which saw Arsenal nearly take the lead after superb work from exciting German winger Serge Gnabry who beat two players before dragging his shot just wide.
Olympiacos, who had lost their opening Group Six game 4-0 to Athletic Bilbao, put Arsenal under more pressure in the second half as Dimitris Rikspun and Elton Monteiro both went close.
Arsenal midfielder Nico Yennaris forced a good save from Eleftherios Choutesiotis in the 54th minute, but opportunities came at a premium as the Gunners struggled to break down a dogged defence.
Both sets of players began to tire but it was Olympiacos that finished the stronger as Soukias and Pinto scored the two goals to inflict a first defeat on Arsenal.