Napoli had a comfortable 3-0 lead through a Lorenzo Insigne brace and Dries Mertens free kick, despite Lukasz Skorupski parrying a Mertens penalty.
“That's just what we're like," shrugged Sarri in his Press conference after the 3-2 win.
“We came back out for the second half and after 20 minutes we assumed the game was over. We became passive and therefore ran a huge risk.
“It's a limitation we have already shown on other occasions, but we are working on it and hope we can improve this. There are many positive aspects in a stadium where Napoli had never won before, such as an excellent first half.
“At the end of a game, a Coach has to shut up and see how his players react, to understand if they've got the right mentality. Some enter the locker room happy, others swear a big, there are those who are really angry. Some were truly livid today, so hopefully the rest of the group can cling to those in a ferocious mood.
“We are growing, but a team that plays a second half like this cannot have strong ambitions. If it happens four or five times a year, that's a massive risk.
“We probably would've conceded an equaliser if it had lasted an extra 10 minutes. Until we resolve this problem, we cannot bridge the gap with the top teams.
“I was glad to see an Empoli side that never gave in and I knew they'd do that. I hope it is a good signal for them to pick up points for the future."