Massimo Maccarone sent Roma 1-0 down at the break, but Philippe Mexes and substitute Riise turned the game around.
“Siena were very organised, good at the counter and had Maccarone on inspirational form,” said Ranieri.
“Despite the fact we were tense and a little afraid, we maintained our self-belief and got back on our feet. It was an emotional debut. The important thing was to get the victory.”
Once again the defence was shaky and could easily have conceded more than one goal at the Stadio Franchi.
“In my view it is not right to criticise just one area of the team, as everyone has to co-operate when going forward and in defending. After all, if the strikers aren't getting supply, it's partly the fault of the midfield.”