Nicola Sansone's wonder strike with 15 minutes remaining gave the Crociati the three points.
"In the second half we did not do very well," he told Sky Sport Italia. "Sansone's goal started from one of our own throw-ins and then we just let him go.
"It was a severe error. It was obvious that we lacked something in the middle of the pitch.
"We should have avoided that goal."