Inter were comfortable 3-0 winners.
"We still need to improve a great deal, as we are too naïve in possession," complained Mazzarri on Sky Sport Italia.
"In the first half the only Catania chances were created by our mistakes. We also wasted too many opportunities when the game was still in the balance. Was I agitated on the touchline? I always am when I see things that aren't going well, that's my job."
The change of tactics has enabled Mazzarri to get the best out of Nagatomo and Jonathan on the wings.
"I didn't think they'd understand so quickly what I wanted from them and especially Jonathan has improved markedly in the last 15 days.
"I can also see the tension the players had from last season wash away with each victory. Winning gives you confidence and in the second half, for example, we came back out on to the pitch with more belief."
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