Sundays would begin and end at a bar called Bollicine – bubbles – behind Piazza Leopardi station in the Fuorigrotta quarter of Naples. It was kept by a man called Enzo Cosenza, who also led choreography and singing in the city’s football stadium. That’s where we spent the time in between, across the span of two years with season tickets, watching Diego Maradona defy the laws of gravity and physics with a football.

I was working in Rome, but commuting from Naples for romantic reasons, and I soon fell in love with Maradona as well. Ahead of Asif Kapadia’s much-anticipated documentary on the Maradona phenomenon, released next week, the talk is once again about Diego. The film turns the pages of a marvellous scrapbook, but doesn’t convey how Maradona and Naples shared a common heartbeat and soul. To understand Maradona in those days was to understand Naples, and vice versa: the same unearthly magic, the same brilliant light, the same maleficient shadows.

Diego Maradona: flight of the enchanter - from the archive, 6 April 1991 Read more

In 1984, SSC Napoli played a stratum below Europe’s soccer powerhouses and wasn’t the obvious destination for a global football star. And this was long before Elena Ferrante and mass tourism: Naples was a place through which visitors hurried to the Amalfi coast, clutching their wallets, often in vain.

Yet it was the perfect place for Maradona: every Neapolitan felt the hand of God in Maradona’s arrival among them. By wresting the city’s first ever championship titles from the hated, hitherto dominant, teams of the rich north, Maradona incarnated the rebellious pride and elan of the poorer south. “Here come the Neapolitans – what a stench! Even the dogs run away,” visiting Milanese fans would sing. “Cholerati! Terremottati!”– cholera-ridden, “earthquaked”. And from our beloved Curva B end of the stadium, led by Cosenza, came the reply: “Mamma, why does my heart beat so? Because I’ve seen Maradona, I’m in love.”

I was in the Curva B the night Italy faced Argentina in the 1990 World Cup semi-final in Naples, when Maradona’s national team shattered the host country’s fairytale. And there was salt in the wound: “Napoli non è Italia” (“Naples isn’t Italy”) Maradona had insisted, urging that the Ultras commit treason and support Argentina. They did, and were never forgiven. But there was logic to the choice; a thread of Parthenopean identity reaching back from the Bourbon Kingdom of Two Sicilies to vengeance in the present by the messiah from Buenos Aires.

The synergy between player and city cut still deeper. Naples exists on a faultline and in the shadow of a volcano, in close proximity to the cults of death and after-life, replete with what northern Europeans and Protestants call superstition. “You don’t know what you missed,” read graffiti on a cemetery wall after the second championship in 1990, when celebrations lasted three nights. “How do you know we missed it?” came a retort.

Facebook Twitter Pinterest A makeshift shrine in Naples in 2004, after Maradona was hospitalised with heart problems. Photograph: Salvatore Laporta/AP

I knew Neapolitans who read cards in earnest, and interpreted dreams with numeric systems. Before the tourists, the canyon-street of peeling stucco called Spaccanapoli was lined with wart-faced marionettes, masks and pulcinelle harlequins, steeped in folklore.

Catholicism in Naples can be richly occult: in the chapel of Sansevero, the marble veil over Christ’s body is so impossibly thin it must have been draped over him and turned to stone by magic, so they say; in a crypt below are the skeletal remains of a couple whose vascular systems are petrified by an 18th-century alchemist’s experiment.

What’s this got to do with Maradona? Everything. Maradona practised sorcery on the pitch; he played voodoo football. Maradona could mind-read and outwit a spellbound opponent’s motive before he knew it himself. No player can be a team, but Maradona’s sixth sense infused those alongside him; his captaincy was seance, as was his communion with Naples. Maradona played pagan football for a pagan city, and that was why it loved him.

Then there was the dark side. Spending half my life in Naples, it was impossible to avoid, and avoid writing about, the Camorra. These were years of sorpasso – overtaking – of Sicily’s Cosa Nostra by the less hierarchical, opportunistic syndicates of what Roberto Saviano later immortalised as “Gomorra”.

I interviewed a man called Pepe who had known Maradona well, and to whom he had confessed: “I’m not a saint, I’m a football player”

Both Maradona’s work and mine became porous – like so much else in Naples – to toxic omnipresence. I wrote exponentially more about the Camorra’s bloodletting and entwinement with a terrifying power machine operated by the Christian Democrat party, while Maradona, in his eagerness to please and be pleased, was ensnared by the mafia, drinking champagne in a cockleshell bath and frequenting a Camorra joint called the Airone piano bar. Himself a boy of the barrio, Maradona’s story was now both inspiration and cautionary tale: he celebrated the fact that exploitation of his trademark in “unofficial merchandise” gave work “to the poor children of Naples” – the mafia as Robin Hood – and willingly accepted the Camorra’s currencies of cocaine and prostitutes. He got them, and they got him, in equal measure.

So on weekdays between watching him play, I found myself at work on Maradona and the Camorra, listening to his voice on police wiretaps. One morning a Camorra madam called Donna Carmela Cinquegrana put her son Cristino on the line for a chat with his football idol, before procuring two prostitutes for the footballer that night. Italian has no word for “privacy”, and in the tatty baroque courtyards and apartment blocks of Naples there is none, whether Maradona craved it or not. Naples adulated but devoured him. I interviewed a man called Pepe who had known Maradona well, and to whom he had confessed: “I’m not a saint, I’m a football player.”

Diego Maradona fell, as Italians say, “dalle stelle alle stalle”, from the stars to the stables.

Having arrived by helicopter into a stadium packed with 75,000 just to greet him, he was now summoned for interview by magistrates and fled Naples ignominiously. The city without Maradona felt, I wrote then, “like a deck of cards stripped of both its joker and its ace”. But Naples adored him too much to feel betrayed; besides, Maradona had shared its vulnerabilities and pain, as well as caused its deliverance.

But Maradona remains in Naples’ heart as he always was: enchanter, saviour, talisman, wizard. His portrait adorns wretched apartment blocks, his maquette figurine is ubiquitous. The city has never really recovered from Maradona since the moment someone wrote, the day after his departure, on a wall in the tumbledown Forcella quarter: “Diego Facci Ancora Sognare” – “Diego, make us dream again”.

• Ed Vulliamy was the Guardian’s Italy correspondent from 1989-1994