Rayan Ait-Nouri canceled out Ibrahima Konate's opener for Liverpool before Mohamed Salah converted a penalty won by Diogo Jota for the 2-1 win.
Slot later said, "The goal we conceded was definitely avoidable and it was unnecessary. It came at a bad time because we had total control over the game.
"By conceding this way, they came back into the game and the good thing for us, is we immediately scored to make it 2-1. With only one goal making the difference, it makes it a difficult game until the end.
"No it wasn’t good, also in the final minutes of the game. The bits in between, I thought we did really well. You also have to give credit to the gameplan of Gary O’Neil. Although it sounds weird, he’s done really well over the last six games.
"He has a really good game plan for every opponent and he it was the same for us today. After the first 15/20 minutes we took more control over the game and we scored the goal as well."