Mertesacker was happy with elements of the team's performance in south Wales, and insists the players must remain focused during a pivotal month in the campaign.
"After 83 minutes we came back into the game and took the lead, and we were quite happy," he told arsenal.com. "It was a difficult match in the first half but in the second half we took the initiative - that was really good.
"At this stage of the season, you have to be consistent. We are in a good way but we have to keep our focus on these games [against Manchester City and Chelsea] and the knockout stages of the Champions League. We have to win those games now.
"We are always looking to win something and we can achieve something with this group. We have a lively group so our thoughts are now on the next match. That's the most important thing for us, not what's going to happen in May.
"We have a few targets in our team that are possible this year. We won't talk about it, we'll just see what happens in the next few important weeks on the pitch."