president Enrico Rocca, and he was acquired by the Serie B side the following year for a notable sum of 37 million Lire, at the age of 19; Riva remained with the Sardinian team for the rest of his career. In his first season with the club, he scored 8 goals in 26 appearances and helped Cagliari to a second-place finish in the league behind Varese, which enabled the team to achieve promotion to the top-flight for the first time in their 40-year history. 1964–1970: Serie A debut with Cagliari and road to the Serie A title The following season, Riva made his Serie A debut for Cagliari on 13 September 1964, in a 2–1 loss against Roma, and also helped the club avoid relegation, leading the team to a comfortable sixth-place finish in the table, scoring an encouraging 9 goals in 32 appearances at the age of 20. This was followed by eleventh, sixth, and ninth place finishes in the league between 1965 and 1968, while Riva also finished as the league's top-scorer for the first time during the 1966–67 season with 18 goals, as the club began to build a potential title winning side around their star striker: Riva attracted several notable footballers to Cagliari, and the team during this period featured key players such as Enrico Albertosi, Roberto Boninsegna, Ricciotti Greatti, Comunardo Niccolai, Mario Martiradonna, Mario Brugnera, Pierluigi Cera, and Nené. Riva subsequently helped Cagliari to a second-place finish in both the Coppa Italia, behind Roma, and the league, four points behind Fiorentina, during the 1968–69 season, winning the capocannoniere title for a second time with 20 goals in 29 appearances; Cagliari had been leading in the league until the 21st matchday, when a loss at home to Juventus caused the team to surrender their lead. Following the arrival of fellow forwards Angelo Domenghini and Sergio Gori from Inter in the summer of 1969, in exchange for Boninsegna, Riva finally won his maiden career Serie A title with Cagliari during the 1969–70 season; under the guidance of manager Manlio Scopigno and his offensive tactics, Riva led the team's front line, scoring several decisive goals that ultimately helped the club win the championship. On 15 March 1970, with Cagliari having climbed to the top of the table with six league games remaining, Riva scored two goals to help Cagliari come back twice from behind in a 2–2 away