“We did well to make it seem easy, but it really was not, as Zenit are accustomed to being in the Champions League," Inzaghi told Sky Sport Italia.
“We have gone beyond the rosiest expectations with eight points from four games. We took two very important draws away from Bruges and St Petersburg despite missing numerous players, but we had to consolidate that with a win today.
“We're getting players back from injury now and it was very important that we get the points this evening."
There were 24 passes involving 10 players in the build-up to Immobile's opening goal.
“These lads have tried to play good football for several years now and I think we did against Crotone on Saturday in impossible circumstances."