Wojciech Szczesny was buoyed by Arsenal's defensive display as the Gunners withstood the threat of Olympiacos to seal three points on Wednesday night.
The home side romped into a two goal lead thanks to Alex Oxlade-Chamberlain and Andre Santos, but were pegged back before half-time by David Fuster.
Arsenal assistant-boss Pat Rice - in the dugout due to Arsene Wenger's UEFA suspension - described the goal as 'really poor to concede' from a defensive point of view.
However, Szczesny was pleased with the resilience the Arsenal backline showed in the second period in order to register their first win of this season's the Champions League group phase.
"It was a very tough game," the goalkeeper told Sky Sports 2. "We knew before the game that it was going to be a very tough game.
"I think you have to give credit to our defence for keeping the result at 2-1 because they did put pressure on us.
"It was a great defensive performance in the second half. We did very well.
"I think we lost the ball too many times in the middle of the park and that created some problems and they looked dangerous on the break.
"We won the first half, we were 2-1 up, it was all about keeping the result that way and we managed to do that.
"I think we knew what we had to do. We had to keep the ball as long as we can. I thought we looked the better side in the second half and deserved the win."