Arsenal boss Arsene Wenger is confident his side can make the Champions League last 16 after setting up a must-win final group game against Olympiakos.
The Gunners' 3-0 win over Dinamo Zagreb at Emirates Stadium on Tuesday, coupled with Bayern Munich's 4-0 thrashing of Olympiakos, means a 2-0 victory or any win by scoring three goals will send Arsenal through to the knockout phase.
Wenger said: "We had to come out of this game with a chance and we have done that - now let's make right what we didn't do right until now."
Arsenal were beaten 3-2 by Olympiakos at home and are in a perilous position after losing their away games to Dinamo Zagreb and Bayern.
Wenger added: "We had to do our job and Bayern had to do theirs and we both did our jobs well. We now have a chance - how big a chance I don't know but I believe we can do it."
Arsenal have lost all three of their previous Champions League games away to Olympiakos, but all in the final group game when qualification had already been assured.
Wenger said: "We just need to win. Obviously I know 1-0 will not be enough but that will be a time where they can lose it and we can win it.
"We know the task and for us this task has one big advantage - it is very clear what we have to do. It is vital we score the first goal.
"It will be tough but I have to believe we can do it."
Arsenal's chances have been revived after they looked slim following their 5-1 thrashing away to Bayern on a night when Olympiakos beat Dinamo Zagreb to strengthen their position.
"I still felt we had a chance after that," added Wenger. "The result on the night was bad for us, especially when Olympiakos beat Dinamo in the last minute."
Wenger expects midfielder Alex Oxlade-Chamberlain to be fit for the game in Greece on 9 December as he recovers from a hamstring injury, while forward Theo Walcott has a chance of being ready after suffering a calf problem.
The Arsenal manager confirmed midfielder Francis Coquelin will be out for 12 weeks after sustaining knee ligament damage in the defeat by West Bromwich Albion on Saturday, although he does not require surgery.