Francesco Totti produced a stunning winner for the 1-0 triumph.
Andreazzoli explained why warming up under the Curva Sud gave them the push they needed.
"Admittedly we haven't played our best until now, but wanted to get the passion from the fans by warming up under the Curva Sud. They were very generous and allowed us to shake off some of those ghosts.
"It had happened in the past too. I was telling my staff about this and Antonio Carlos Zago experienced it first hand, so we knew that it was worth the risk. We haven't done so far what the fans deserve, so it was a risk and we knew there could be a blowback, but I told the lads to go out there with their heads held high, because the Curva Sud would not let us down.
"It gave us a sense of certainty, confidence and the ability to fight Juve in terms of character, quality, organisation and vigour.
"We tried to do everything possible to build up their confidence. We put heart and soul into it."