Rodrigo Palacio's second goal deep into stoppage time helped Inter come from 2-0 down to claim all three points in the race for Champions League football.
Andrea Stramaccioni's side have struggled in recent weeks but Cambiasso believes that his team can build on today's result to finish in the top three.
He told Sky Italia: "In the first half of the game we have suffered a lot, but luckily in the second half when we got back to camp made the first goal.
"Our spirit has grown to lead us to victory. I think it was more a psychological than physical, so it's a win that gives us great confidence for the rest of the season in both the league and Europe."
Tottenham Hotspur are next up for Inter in the first leg of their Europa League last-16 tie on Thursday.