The Nerazzurri snatched a last-minute 1-0 victory in Tuscany thanks to substitute Luc Castaignos.
"We knew that we would have to be humble, fight and suffer for the whole game," said the Coach. "It wasn't easy. Siena defend well and tried to hit us on the counter-attack throughout the match.
"Playing against 11 men who sit in their own final third isn't simple. But I am satisfied, as we take home three points and that's the most important thing."
Ranieri had said Inter were still contenders for the Scudetto despite a terrible start.
"For us, every game is a Final. They are knockouts, in or out, and we've always got to try to win.
"Our ultimate objective is to get back into the Scudetto race, but to do that we must take it one game at a time."