They currently hold a five-point lead over their nearest challengers with four games left to play, but Mazzarri is refusing to talk about a place in the Europa League until their spot is confirmed.
"We did well today, but it's too early to talk about Europe as already secure," he told Sky Sport Italia.
"We still have to play against Napoli, Milan, Lazio and a Chievo side fighting for safety. The League is difficult and we have to take it one game at a time."
Inter's win this afternoon extended their unbeaten run in the league to five games.