“Winter champions!” Maradona said on his Facebook page.
He added in another message: “With great joy I learn about this achievement from Napoli, which we all awaited for so many years. Knowing that Napoli fans today can live such a big joy gives me a lot of happiness. Now I want to win the league. Go boys, go Napoli.”
The 1990 title was Napoli’s second, the first coming in 1987 when they had also led at half-season. Napoli were top as well at that stage the following year but had to settle for second in the end behind AC Milan.
This time around a 5-1 win at Frosinone on Sunday lifted Napoli to 41 points from 19 games at the halfway mark of the campaign, two points clear of Juventus and Inter Milan.
While the fans celebrated and Maradona rejoiced, club officials and players are keeping their feet firmly on the ground.
President Aurelio de Laurentiis thanked Maradona for his words, naming him “a unique player for Napoli’ history and the world of football.”
But he insisted: “The truth is that this year the league is very open, we have a competitive group and a talented manager.”
The class of 2016 also includes an Argentine star, forward Gonzalo Higuain whose brace Sunday lifted him to a league-leading 18 goals but who also shrugged off the winter title.
“Being winter champions is worth nothing,” Higuain said. “What counts is being champions in May. We must tackle all games as if they were finals and continue on like this. We can still improve a lot.”
Napoli boast the league’s best attack with 38 goals and the best goal difference of 23, having conceded 15.
Another key figure is coach Maurizio Sarri, who celebrated his 57th birthday with the big win Sunday but agrees the symbolic title doesn’t mean a lot although some 70 per cent of the winter champions have then also won the league.
“I hailed this performance and it’s a high satisfaction for the fans as well but that’s all,” Sarri said. “In winter the championship doesn’t exist and I should add that the last time we have been the first this year, we failed the following match.
“We are the title favourites, but only for football stats. I have never seen someone win a marathon after having run just half the race.”
Sarri, who was born in Naples as his Tuscan father worked temporarily in the southern city, arrived at the club from Empoli in June, taking over from Rafael Benitez.
A former bank manager with a passion for football, he gradually switched to full-time coaching, leading Empoli to the top flight in 2014.
“I love my job. I love to be able to work here in Naples because it’s something special to me,” Sarri said. “At the beginning of the season I would have never thought to reach the first half of the season as the title favourites.
“I have always been skeptical in my career. However I was calm and determined and now I want just to be focused on the next match.”
For the remainder of the season, he foresees a race with Juventus who have recovered from a poor start with nine straight wins.
“Four titles won in the past four years are no little thing,” Sarri said. “Juventus are the main opponents. I always considered them the big favourites.”