The 24-year-old Italian deputised for the injured
Mannone may have been given little chance with Younes Belhanda's chipped penalty which put the European Cup debutant into an early lead, but otherwise he did all that was required of him.
The goalkeeper pulled off a smart low first-half save from
That followed on from two clean sheets in the Premier League against Stoke City and Liverpool, leaving him very much in contention to start at Manchester City this weekend.
It is a far cry from the scenario facing Mannone after a calamitous display in a Champions League game at Olympiacos last December, which then saw him farmed out on loan to Hull and at the time perhaps out of Arsenal's future plans.
However, a productive four-month spell of regular football - during which he kept a club record six consecutive clean sheets - helped sharpen Mannone's focus.
"Every goalkeeper has his own path, and I had mine. I had bad times and I just rolled up my sleeves and worked hard. Then, I thought: 'Let's go to Hull'," he said.
"Nobody wants to go there really, but I found a good club, good fans and I gained experience.
"I played games as a number one - 24 games in a row - so that's what I needed.
"It helped me going onto the pitch thinking: 'Okay, I can be number one now'.
"The keeper is one of the most important positions because you can make a save and bring the three points home or you can do a mistake and everything is your fault. I am ready for it.
"Before the Southampton game the boss talked to me, and for the first time I felt he understood I was ready to be number one.
"I hope, after this result, something has changed."
Mannone feels going through his Athens humiliation - where he made a complete hash of attempting to scissors-kick the ball clear as it bounced on into the empty net - saw him come out a stronger person.
"It is a game where, I know you find it crazy, but it was a good lesson for me," he said.
"I had another mind at the time. It was almost one year ago and my mentality was I was nearly away from Arsenal. I was expected to go on loan. I didn't feel confident.
"I had not played for a year-and-a-half, and at the time, my mind was not ready.
"I did not help myself because I needed to be sharp and always on my toes."
It was an experience which the former Gunners defender claimed left him with a 'headache and a half', but maintained the belief ahead of this weekend's trip to take on the Premier League champion.
Germany centre-back Per Mertesacker - part of a rearguard which has only been breached twice this season - sees no reason why Arsenal cannot head to the
"We are convinced that we can stay in the league, at the top, and that's our target for Sunday," he said.
"Last year we lost at Man City. It was a very tight game so we will try to do better this time."
Mertesacker added on Arsenal Player: "I feel like we are in a better shape than last year, because we are now in a good shape from the beginning [of the season]. I think we are well prepared now."
UEFA Champions League
UEFA has announced that the Champions League final in 2015 will take place in Berlin's