Italian football was mourning one of its most important ever players on Monday after iconic striker Luigi "Gigi" Riva died aged 79.

Nicknamed "Roar of Thunder", Riva is Italy's all-time top goalscorer and famous in the Mediterranean nation for firing Cagliari to their only league title in 1970.

Cagliari said "Forever GIGI RIVA" in a short post on X, formerly Twitter, which was accompanied by a picture of their hero in the prime of his career.

"Italian football is in mourning because a genuine national monument has left us today," said Italian Football Federation (FIGC) president Gabriele Gravina.

Riva's death is of such significance that a minute's silence was held before the start of the second half of the Italian Super Cup final, played on Monday in Riyadh.

"Ciao Gigi" was displayed on the screens at Al-Awwal Park in the Saudi Arabian capital, alongside a picture of the deceased Riva.

"He will always be remembered for his play with 'his' Cagliari and the national team," said Serie A in a short statement.

Matches across Italy from Monday until the end of the coming weekend will hold a pre-match "minute's reflection" in honour of Riva, added the FIGC.

Riva had been in hospital in Sardinian capital Cagliari, where he stayed after the end of his playing career, reportedly after suffering a heart attack over the weekend.

Riva scored 35 times in just 42 appearances for his country, with whom he won the 1968 European Championship and reached the World Cup final two years later.

Italy were swept aside in that final in Mexico by Pele's Brazil, considered one of the best teams in the history of football, but he scored a key goal in the dramatic 4-3 defeat of West Germany in the last four.

Riva's Italy career was hampered by two serious injuries, including a broken leg in 1970 which also ended Cagliari's bid for a second straight league title.

"It's a huge loss for me, we had been friends for a very long time, since 1967. We did military service together," former Italy goalkeeper Dino Zoff told the AGI news agency.

Riva played almost his entire club career with Cagliari, a club more familiar with relegation then glory, despite being persistently courted by powerhouse Juventus.

He signed for Cagliari in 1963 and retiring in 1976 after topping the Serie A charts three times and netting more than 200 times for the island club.