Gianluca Lapadula scored a double as promoted Lecce punished a wasteful Napoli who collapsed to a 3-2 defeat at home in Serie A on Sunday.
Gennaro Gattuso’s side had rekindled hopes of European football next season after league wins over Juventus and Sampdoria, and eliminating Lazio from the Italian Cup.
But after a bright start to the match in Naples southerners Lecce punished the hosts to earn their first league win since November 30.
“The biggest concern is the fragility of the team today,” said Gattuso.
“We’re living in fear. We didn’t hurt them in the first half an hour when we had five or six shots on goal. We were too passive.
“I saw a team who struggled to help themselves.
“We had a great opportunity to go up in the standings. For me today we were not a team.”
Lapadula broke through after half an hour, scoring the first of his double, with Marco Mancoscu sealing victory with a superb free kick eight minutes from time.
Arkadiusz Milik had levelled for Napoli just after the break with Jose Callejon reducing the deficit late.
The hosts were furious at being denied a penalty for a foul on Milik on front of goal, with the Pole booked for simulation.
“It’s not right,” said Gattuso. “If there is Var, you should to go and have a look at Var. It costs nothing.”
Napoli sit 11th four points off the Europa League berths, with Lecce earning a valuable three points as they sit above the relegation zone.
Elsewhere, Mario Balotelli’s Brescia earned a point with a 1-1 draw at home against Udinese in new coach Diego Lopez’s first game in charge for the basement club.
Jeremie Boga scored late to grab at 2-1 win for Sassuolo at SPAL.
At the top of the table, Inter Milan have a chance to pull level with leaders Juventus later on Sunday when they take on Zlatan Ibrahimovic’s AC Milan in a derby clash at the San Siro.
Lazio are four points behind Juventus in third before they travel to Parma.