Cole Palmer and Malo Gusto struck the goals for the hosts.
Maresca said afterwards: "We’re very happy and this was a very important win for us.
"Everton have been on a good run in recent weeks and came here in good form. We’ve dropped points in the last week, so it was important to get the win.
"We knew it would be a difficult game but I thought we did very well and completely deserved to win the game. The effort from the players today was top and it was a good, important victory as I said."
The Italian also said: "I’m very happy for Cole (to score) and as I’ve said many times before, we are a better team with him in the side.
"But I really want to praise all the players and the squad, because we’ve had a lot of games recently. We’ve also played five games without Moi (Caicedo), 11 without Cole and almost all the games without Liam (Delap).
"There are important players for us and I’m sure people can appreciate that. It’s very important for Cole and hopefully it will give him a boost. Today was also important for all the players and the fans too. We are very happy with the result.
"Cole needs to be fit and that’s why we will manage him carefully. Hopefully we can keep him fit, that’s the most important thing, and hopefully he can be a help to us going forward.
"The effort is there from the players, you can see that. Reece (James) and Malo are both full-backs but today, they both played as midfielders They caused many problems in the offensive areas.
"I’m very happy for Malo in that moment to score, he deserved his goal but I’m also happy for the team overall, for the performance we put in today. Now we must build on it."