Cesc struck twice in the come from behind 3-2 win.
"We felt comfortable at all times, we dominated the match, but sometimes it can get complicated and we have to show our character - and that's what we did," he said.
When asked to comment on the criticisms he's received lately, Cesc said: "I've always been at ease, I think there are a lot of people that needed to talk, opine and write stuff but nothing is wrong. I'm tranquil because I've gone through rough times before and I always manage to score again.
"Besides, it's much easier when you're playing with quality players like Xavi and Messi."