Napoli have sacked Carlo Ancelotti, one of Europe's most successful coaches, less than an hour after they beat Genk 4-0 to qualify for the Champions League round of 16.
The victory on Tuesday snapped a nine-match winless run in all competitions.
The club confirmed it had dismissed the 60-year-old Ancelotti - who has won domestic league titles in England, France, Germany and Italy and the Champions League three times - in a statement.
He was 18 months into a three-year deal.
"Napoli has decided to revoke the position of first-team coach from Carlo Ancelotti," the club statement read.
"The relationship of friendship, esteem and mutual respect between the club, its president Aurelio De Laurentiis and Carlo Ancelotti remain intact."
The decision followed a tense few weeks at the club during which Ancelotti criticised a decision by De Laurentiis, Napoli's flamboyant owner, to confine the team to a training-camp for a week.
The players broke off the camp halfway through, refusing to stay in the hotel although they continued to train.
At the same time, Napoli, runners-up in Serie A for three of the past four seasons, suffered a slump in form which saw them drop to seventh in Serie A.
Ancelotti's dismissal had been widely predicted by the Italian media who said Napoli had lined up Gennaro Gattuso, fired by AC Milan at the end of last season, as his replacement.
Ancelotti described their Champions League campaign, which saw them complete Group E unbeaten, as "one of the few satisfactions we've had this season and much of that is our fault."
He has denied throughout that there has been conflict within the squad or between the players and the club's management.
"The problem here is that the team has not been able to express its full value, but there were no clashes, apart from isolated incidents that happen everywhere," he said.
Ancelotti was hired to replace Maurizio Sarri and his arrival, after nine years' coaching abroad, was regarded as a major coup by De Laurentiis who rescued Napoli from bankruptcy in 2004 and turned them into Serie A title contenders.
Sarri had turned Napoli into the neutrals' favourite thanks to their flowing, attractive football but they always fell short of Juventus, who have won eight successive Serie A titles.
Napoli hoped that Ancelotti, who was also sacked in his previous job at Bayern Munich after less than two seasons, could give them the killer punch they had lacked under Sarri.
After finishing second last season while overhauling the side, Ancelotti had said he was ready to launch a serious bid for the title this term.
Yet their campaign imploded amid a run of matches which saw them miss chances, concede sloppy goals and the normally-placid Ancelotti sent off for disputing a VAR decision.