Napoli ended a nine-match winless run in all competitions to reach the Champions League last sixteen on Tuesday as a first-half Arkadiusz Milik hat-trick set up a 4-0 win over Genk in what was coach Carlo Ancelotti's last stand.
Hours after the game, the Italian club dismissed Ancelotti, saying in a statement that: "The relationship of friendship, esteem and mutual respect between the club, its president Aurelio De Laurentiis and Carlo Ancelotti remain intact."
Former Chelsea, Real Madrid and Bayer Munich coach Ancelotti led Napoli to second place in Series A last season but his team has suffered a loss of form this term and he fell out with club owner Aurelio De Laurentiis after he ordered the players to be confined to a week-long training camp.
Genk's Maarten Vandevoordt, who at 17 years and 287 days became the youngest goalkeeper to play in the UEFA Champions League, had a nightmare start as he gave the ball away under pressure and allowed Milik to score in the third minute.
The Pole fired the second in the 26th minute and converted a penalty in the 38th before Dries Mertens, on his 300th Napoli appearance, completed the scoring with another penalty a quarter of an hour from the end.
Napoli finished second in Group E with 12 points, one behind Liverpool, while their Belgian opponents finished bottom of the group with one point. Salzburg came third to qualify for the Europa League last 32.
The hosts came out to a lukewarm reception, with the San Paolo stadium less than one-quarter full, but Napoli responded brightly, Kalidou Koulibaly scraping the crossbar with a header before the opening goal.
Vandevoordt collected a pass in his penalty area but was pressured by Napoli forwards and Milik had an easy job to score as the teenager lost the ball.
After Joseph Paintsil skimmed the post for Genk, Napoli went further ahead when Allan sent Giovanni Di Lorenzo down the right and his cross was turned in at the near post by Milik.
Allan then sent Calderon through and he flicked the ball over Vandevoordt, was tripped and Milik converted from the spot.
When Casper de Norre gave away another penalty with a handball it was Mertens who converted with a Panenka-style chip down the middle of the goal to complete Nepali's first win since Oct. 23.