Second-placed Napoli dropped two valuable points in their Serie A title chase when they were held to a 0-0 draw at home on Sunday by table-propping Chievo, who were playing their first match under their third coach of the season.
Lorenzo Insigne hit the post with a long-range drive and defender Kalidou Koulibaly also clipped the woodwork with an acrobatic effort but, apart from those second-half efforts, Napoli lacked creativity and struggled to create openings.
Domenico Di Carlo became the latest coach to sit in the Chievo hot seat after Lorenzo D'Anna was sacked in October and his replacement Gian Piero Venturo quit after four games.
The Flying Donkeys, who have the worst defensive record in Serie A with 30 goals conceded in 13 games, defended bravely and also hit the post with a first-half Joel Obi effort.
The result left Napoli eight points behind leaders Juventus, who beat SPAL 2-0 on Saturday, while Chievo stayed bottom with one point, having had three deducted over accounting irregularities.
"We had too little intensity at the start," said Napoli coach Carlo Ancelotti. "When Chievo were more open, we did not take advantage of the spaces and in the second half, they closed up."
Ancelotti added that he did not want to discuss the eight-point gap with Juventus.
"I will evaluate the rankings when we are halfway through the season. Now we are thinking about the commitments that await us," he said.