He only took charge on Thursday after Gian Piero Gasperini's dismissal, but secured their first victory of the season in all competition.
"It was important to start on the right foot, as the lads have to get back on track," said Ranieri after the 3-1 result over Bologna.
"I had asked for the performance, which was more important than the result. It was crucial that we fight for 90 minutes and this was a good game.
"The first half was positive, we allowed Marco Di Vaio only one scoring opportunity. We were very practical and also entertaining in some moments. Coutinho gave us the lightness of touch that we needed and the rest of the squad was compact.
"After the break Bologna pushed hard and I made the changes I thought were apt."