The Serie A side progressed to the semi-finals 3-1 on aggregate following their second-leg win, but required a deflected goal from the Italy international to kill off their opponents.
"We absolutely knew that it would not be easy to reach the semi-finals," he told Sky Sports News. "We started very well. Then, however, we suffered a little setback when they equalised.
"It's clear that my goal was a little lucky, but now we will go forward and fight right until the end with our intent to complete our objectives."