Alexander Isak and an Axel Disasi own goal saw Newcastle win 2-0 on Wednesday night.
Maresca said afterwards: "I think it worked if we analyse the performance. If we analyse the result, it didn't work. But I think for 22 or 23 minutes, until their goal, we were in control of the game, we didn't concede nothing.
"But then after the goal, we lost the control for 10 minutes and then conceded the second one. In the last 10 minutes of the first-half, we had two or three clear chances that unfortunately we didn't score.
"In the second-half, we were in control of the game. The most important thing, as we always say, is the result but the performance, we lost the game because of 10 minutes after the first goal and then for the rest, we were quite good."
On exiting the Cup, Maresca said: "We said, all the competitions are important, for sure, but also now we have different competitions that are still there and we can be more focused on that. We are sad that we lost the game, for sure, because we said many times this is something we don't like. Now, we have two games to prepare for the next game."