Arsene Wenger hopes his young Arsenal side will have learned a hard lesson in European football after they allowed Shakhtar Donetsk to fight back and win their Champions League Group H clash at Donbass Arena last night.
England forward Theo Walcott had slotted home a fine breakaway goal after 10 minutes for the injury-hit Barclays Premier League side, who were without captain Cesc Fabregas.
However, Shakhtar - trashed 5-1 at Emirates Stadium a fortnight ago - responded well and were eventually rewarded when 19-year-old Craig Eastmond, making his European debut, diverted Dmytro Chygrynskiy's header into his own net.
Former Gunner Eduardo - who had scored a late consolation goal in north London - slotted home from close range on the stroke of half-time, which proved enough to force his old club to wait for qualification to the knockout stages as Arsenal failed to take the chances which came their way in the second half.
Wenger had warned his team not to expect another European romp against a side which boasted an impressive home record, the Miners having kept clean sheets in nine from 10 matches, and lost just two of the last 30 games in all competitions.
"We have learned the lesson that at this level you cannot lose focus at any moment and that is why we were punished," said the Arsenal manager, "but we are still in a strong position in the group.
"We had a good start, but after we lost our urgency and let Donetsk come into the game too much.
"We lost concentration in the duels and you could see what was coming towards half-time.
"I felt we moved out of the game altogether and moved into the game altogether, so it was more of a team problem, a kind of complacency problem more than an individual problem.
"In the second half we came back into the game and gave a lot, you cannot fault the team, and we were a bit unlucky."
Wenger challenged his side to maintain their battles on all fronts.
"At the moment we are not in a position where we can choose - we have to fight," the Arsenal manager said.
"We have a difficult league game on Sunday against Newcastle.
"We will win what we can and not choose too much."
Shakhtar Donetsk coach Mircea Lucescu had been critical of the referee from the last meeting at Emirates Stadium, a subject he again brought up following last's victory.
However, the Romanian coach was pleased with his side's efforts.
"It was a good match and an important win for me. I have been waiting for it a long time," he said.
"I liked the reaction of my team, they played at a good level.
"Arsenal are a really good team, and we had to earn the points."