The 34-year-old scored the second goal for the Bianconeri as they took all three points with a commanding performance against their Serie A title rivals.
"We tried to send a signal to those in front of us, to let them know we're going to have a great season," Pirlo told Sky Sport Italia.
"The two defeats to Fiorentina and Real Madrid helped us to grow. Now we have rediscovered ourselves and must continue along this path.
"[Roma] and Napoli will be in the title fight to the end. We just have to focus on ourselves."
Juve are now one point behind leaders Roma.