Alessandro Del Piero claims that the defeat to Palermo on February 2 was a turning point in Juventus' season.
The Old Lady played well in Sicily, but lost 2-1 and felt hard done by after the referee failed to give a penalty.
Results have picked up a lot since then.
Juventus climbed to sixth place in the table on Sunday following a 1-0 victory over Inter in the Derby d'Italia.
"I am really happy for Sunday's win because we needed a game of that nature not just to continue the progress we made with the three points away to Cagliari, but above all with the defeat to Palermo," Del Piero said.
"In my opinion the disappointment we felt in the dressing room at the Renzo Barbera is where the desire to change sprung from and it allowed us to start all over again and to get the result we needed on Sunday.
"Obviously we mustn't just content ourselves with beating Inter. We are only talking about one step, but the road is still long. Now we need continuity in our upcoming games to find the position in the table which is closer to our ambitions.
"Of course, Sunday's game must increase our self esteem and the consciousness in our own means. We can play and win games this way and this is important.
"As for me I am happy with what my teammates did on the pitch."