Carlo Ancelotti gave former protege Gennaro Gattuso a lesson in football as Napoli came from two goals down to beat AC Milan 3-2 in Serie A on Saturday.
Ancelotti -- who took over as coach of the Italian league runners-up this summer -- was in charge of his first home game at the San Paolo Stadium.
The 59-year-old's side also trailed before getting past Lazio 2-1 in the season opener in Rome last weekend.
AC Milan were playing their first match of the season after their game against Genoa was postponed because of the bridge disaster in the port city.
But it was to be a bitter defeat for Milan coach Gattuso, 40, who played under Ancelotti when the latter was in charge of AC Milan, winning the Champions League together in 2007.
Ancelotti praised the "great desire ... to fight back vehemently," by his side.
"I have a fond memory of all my former players, but with Gattuso there is something special.
"It's a wonderful evening, one full of emotions for me.
"Milan hadn't really given many signs of being dangerous in attack, but surprised us with two goals.
"It was very difficult in that situation, then we changed system and the crowd pushed us on to turn it around."
Ancelotti spent most of his career at AC Milan, winning three Serie A and four European titles as a player and coach with the northern giants.
His last coaching job in Italy -- before nine trophy-laden years abroad at clubs including Chelsea, Paris Saint-Germain, Real Madrid and Bayern Munich -- was at the helm of Milan.
Gattuso had said it was his dream to defeat his old "maestro" as Ancelotti had done as AC Milan coach over two decades ago beating his former boss Arrigo Sacchi's Parma.
"It hurts me to play so well at the San Paolo and then emerge empty-handed. Now we have to lick our wounds and go forward," said Gattuso.
Giacomo Bonaventura sensationally opened for Milan after 15 minutes with a Davide Calabria half-volley giving the visitors a two-goal advantage four minutes after the break.
But Piotr Zielinski bagged a brace for Napoli in a 15-minute second half spell with substitute Dries Mertens sealing victory 10 minutes from time.
"It's acceptable to make a mistake but not to disappear from the pitch," said Gattuso.
"After we conceded the first goal we stopped playing."
Argentine striker Gonzalo Higuain made his competitive debut for Milan but had little impact in his old stadium, along with new on-loan Chelsea midfielder Tiemoue Bakayoko.
Cristiano Ronaldo made his home debut for Juventus in a 2-0 win over Lazio, which after last week's 3-2 win at Chievo gives the champions a maximum six points.
Ronaldo is still waiting for his first goal with his new club with Miralem Pjanic putting the hosts in front at the Allianz Stadium after half an hour with Mario Mandzukic scoring the second on 75 minutes.
Napoli play at Sampdoria next week with AC Milan looking for their first points at home against Roma, and Juventus travelling to promoted Parma.
Lazio look for their first points against newcomers Frosinone.