The Gunners won 3-0 in a highly impressive performance on Wednesday evening.
The Gunners travelled to Greece needing a win by two goals, or by a one-goal margin after scoring three times, in order to advance from Group F.
That was after they made things difficult for themselves by losing three of their five games before the final round of fixtures, with the Greek side having beaten them at the Emirates.
They managed to squeeze through against the odds, though, with an Oliver Giroud hat-trick seeing them to a 3-0 win and what had been an unlikely progression at one stage.
It was a victory that few saw coming, but Cech says that he and his teammates always believed that they would prevail.
“Well, we could!” he answered to the club’s official website when asked if anyone saw the result coming.
“We were searching for it and we knew if we played our game, if we have a great team performance and great individual performances then we will have a chance.”
“We did say exactly that. The first goal was important because going 1-0 ahead, they knew that one goal would not take us through and were holding back as one goal can kill the game for them.”
After such an impressive victory to secure passage to the latter stages, it will now be interesting to see how Arsenal approach the competition.
With a second placed finish, they are sure to face one of the tougher sides left in the competition, meaning a place in the quarter-finals will be a hard one to attain.
With a potential Premier League title challenge on the cards, that may be a sacrifice Arsene Wenger is willing to make to end their drought.
Confidence will be flowing, though, meaning there is no reason why they can’t compete on both fronts, especially if they can replicate Wednesday’s performance.