Khouma Babacar, Juan Cuadrado and Nenad Tomovic were all on target as Fiorentina routed Inter 3-0, sending out an ominous warning to their Serie A rivals.
It was only Fiorentina's second win of the campaign, having lost their season opener and drawn three since.
But the Florence club - expected to challenge for the UEFA Champions League places - are slowly rising up the standings and Montella expressed his delight with the manner in which Fiorentina played at the Stadio Artemio Franchi.
"Aside from the result, we had a top level performance against a great team with excellent players," Montella told Sky Sport Italia.
"We had the perfect performance right when we needed it, proving my players have the temperament needed to do well this season.
"I had seen this maturity in other matches too, but when you don't take your chances then it’s tough, especially against teams who come to get a draw.
"There were moments of huge pressure on Inter, others in which we defended deeper, so I am extremely happy that all our characteristics were on show at the right time.
"A week ago people said we had to survive in Serie A, now there's talk of third place again. We have to continue our way with our style of football and doing what our fans want to see. It's a starting point to move on from."
Meanwhile, goalscorer Cuadrado refused to shed light on his contract situation when quizzed by reporters after he was the subject of interest from European giants Manchester United and Barcelona during the transfer window.
"How are talks going? I don't know and I am not thinking about it. I leave all that to my agent," the Colombia international said.