Per Mertesacker says that scoring first against Liverpool gave Arsenal the momentum to go on and win their FA Cup tie.

Arsène Wenger's went into Sunday's game with memories of the previous weekend's heavy defeat at Anfield relatively fresh in their minds, and Liverpool threatened to take the lead after another fast start.

But Lukasz Fabianski kept the visitors out, Alex Oxlade-Chamberlain's first-half strike lifted Arsenal's confidence and they secured a morale-boosting 2-1 win to reach the last eight.

The first goal was key. Fabianski kept us in the game several times

"It was obviously very important for us, after the defeat at Anfield," said Merteacker. "That defeat was a massive blow for us but we came back in the FA Cup. It was a different competition and a different game.

"The first goal was key. Fabianski kept us in the game several times. It was very important to get a good performance and after Liverpool's early chance we were much better in the game. We deserved our first goal and the second one was vital as well."

Mertesacker is now focused on an even tougher test - Bayern Munich in the Champions League.

"That's a big duel against the German side," he said. "I think [they are] one of the best teams in the world at the minute but [it's] another home game and we are very confident at the moment with home games.

"We haven't conceded a lot in the last couple of weeks so confidence is good for next week."

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source Chris Harris 17 Feb 2014