Nick Woltemade scored twice as Newcastle jumped to a 2-0 lead before being pegged back by Reece James and Joao Pedro.
Maresca said afterwards: "I think after the first half they deserved to win the game, for sure. From my point of view, after the second half, we deserved to win the game.
"I think after the second goal we scored we had three or four clear chances to score one more. They also had one more with (Harvey) Barnes that I remember, but overall I think a draw is the correct result.
"The key to the first half for me was the first goal we conceded, because after a few minutes we conceded a goal and the game goes in the direction that they want. So that goal we conceded for me was the key.
"Then in the second half, we scored twice, we could have scored more goals, we changed some things at half-time. But at this stadium, 2-0 down at half-time, you come back, it is not easy for any team."
On the fight-back overall, Maresca added: "For sure in the first half we have things that we can do better, but the way they showed in the second half character, togetherness, they have to feel proud.
"Being 2-0 down against Newcastle away, in this stadium, in this noise, in this environment, it is not easy, not many teams could do that, and they have done it."