Ranieri admits "we would not have been able to turn this game around at the start of the season," as Roma have changed mentality.
"I don't know if it will be an historic night. It was important to get points against the vice-Champions of Europe," he said of the 3-2 victory against Bayern Munich.
"It was incredibly difficult after that first half, but the lads fought with hunger, determination and desire, helped by the great crowd.
"We weren't that bad in the first half, it was just that they stretched us out and were very good when in possession, as it forced us to run a lot. That's why I moved Mirko Vucinic and Jeremy Menez to wider roles so we could cause them some problems.
"We changed gear and right after the break the first few chances were crucial, as they got the crowd back on side and they too started to believe in us."