Diego Armando Maradona Franco (Spanish pronunciation: ['djego mara'dona], born 30 October 1960) is an Argentine retired professional footballer and manager. Many in the sport, including football writers, players, and fans, regard Maradona as the greatest football player of all time. Maradona was joint FIFA Player of the 20th Century with Pele. An advanced playmaker who operated in the classic number 10 position, Maradona is the first player in football history to set the world record transfer fee twice, first when he transferred to Barcelona for a then world record PS5 million, and second, when he transferred to Napoli for another record fee PS6.9 million.

Maradona arrived in Naples and was presented to the world media as a Napoli player on 5 July 1984, where he was welcomed by 75,000 fans at his presentation at the Stadio San Paolo. Sports writer David Goldblatt commented, "They [the fans] were convinced that the saviour had arrived." A local newspaper stated that despite the lack of a "mayor, houses, schools, buses, employment and sanitation, none of this matters because we have Maradona". Prior to Maradona's arrival, Italian football was dominated by teams from the north and centre of the country, such as A.C. Milan, Juventus, Inter Milan and Roma, and no team in the south of the Italian Peninsula had ever won a league title. At Napoli, Maradona reached the peak of his professional career: he soon inherited the captain's armband from Napoli veteran defender Giuseppe Bruscolotti and quickly became an adored star among the club's fans; in his time there he elevated the team to the most successful era in its history. Maradona played for Napoli at a period when North-South tensions in Italy were at a peak due to a variety of issues, notably the economic differences between the two. Led by Maradona, Napoli won their first ever Serie A Italian Championship in 1986-87. Goldblatt wrote, "The celebrations were tumultuous. A rolling series of impromptu street parties and festivities broke out contagiously across the city in a round-the-clock carnival which ran for over a week. The world was turned upside down. The Neapolitans held mock funerals for Juventus and Milan, burning their coffins, their death notices announcing 'May 1987, the other Italy has been defeated. A new empire is born.'" Murals of Maradona were painted on the city's ancient buildings, and newborn children were named in his honor. The following season, the team's prolific attacking trio, formed by Maradona, Bruno Giordano and Careca, was later dubbed the "Ma-Gi-Ca" (magical) front-line. Napoli would win their second league title in 1989-90, and finish runners up in the league twice, in 1987-88 and 1988-89. Other honors during the Maradona era at Napoli included the Coppa Italia in 1987, (second place in the Coppa Italia in 1989), the UEFA Cup in 1989 and the Italian Supercup in 1990. Despite primarily playing in a creative role as an attacking midfielder, Maradona was the top scorer in Serie A in 1987-88, with 15 goals, and was the all-time leading goalscorer for Napoli, with 115 goals, until his record was broken by Marek Hamsik in 2017. When asked who was the toughest player he ever faced, A.C. Milan central defender Franco Baresi stated, "Maradona; when he was on form, there was almost no way of stopping him," a view shared by his Milan teammate Paolo Maldini, who stated, "The best ever I played against was Maradona." While Maradona was successful on the field during his time in Italy, his personal problems increased. His cocaine use continued, and he received US $70,000 in fines from his club for missing games and practices, ostensibly because of "stress". He faced a scandal there regarding an illegitimate son, and he was also the object of some suspicion over an alleged friendship with the Camorra. Later on, in honour of Maradona and his achievements during his career at Napoli, the number 10 jersey of Napoli was officially retired. CANNOTANSWER

Using a quote from the above article, answer the following question: What happened at the peak of his career?

Napoli would win their second league title in 1989-90, and finish runners up in the league twice, in 1987-88 and 1988-89.