Scoring goals is what he was born to do and he was the driving force in the Sardinian club’s first and only Serie A title, won in 1970.
His talents - 164 goals in 315 games for Cagliari - even helped him pass his driver’s license.
Speaking to Italian news outlet Gazzetta dello Sport, he explained his move to the club from Legnano in 1963 afforded him the luxury of a car - a Fiat 600 he owned with mates - which legally he couldn’t drive.
Luckily for Riva, the Amsicora Stadium had a running track inside where he practiced driving in secret before taking his test under the supervision of an avid Cagliari fan.
“The instructor told me he would pass me if I scored on Sunday. I managed two in Verona and got my license.”
But his prowess in the box also meant Italy's established big guns were always sniffing around.
Now, undoubtedly Riva led a comfortable life being the focal point and the team's star man, but his bank balance could have been so much bigger if he wanted.
Football was always first with him, though, which is presumably why his head was never turned by the riches on offer at Italy’s elite clubs, as Juventus chief Giampiero Boniperti can attest to.
He tried to sign Riva in 1967, but the bond between player and club had been forged over many many years following his arrival on the island as a 19-year-old.
“I would have earned triple [at Juve],” he told Gazzetta dello Sport of his decision to remain at Cagliari, explaining that, in his eyes, joining Juventus would have been a cowardly move.
“Sardinia had made me a man. It was my land. In those days, they called us shepherds and bandits around Italy. I was 23 and the great Juve wanted to cover me in money.
"I wanted the Scudetto for my land. We did it, the bandits and shepherds.”
The title came three years later, with Riva the top scoring striker in the league. Then Juve came calling in 1973.
This time the offer was reported to include numerous Juve players and £1.5m fee. Riva was 29 by this point and surely you don’t say no to Juventus twice?
He quickly told them where to go because it seems one title with his beloved Cagliari was worth more than anything he could have won with Juventus.