On 22 November 1969, Riva scored a famous diving header in a 3–0 away win in a World Cup qualifying match against East Germany, at the Stadio San Paolo in Naples, which sealed Italy's place at the 1970 World Cup; prior to the tournament, he had scored 19 goals in only 16 matches. At the 1970 World Cup in Mexico, much was expected of Riva; however, he initially underperformed in the first round, failing to score in each of Italy's three group matches, although both Riva and his strike-partner Angelo Domenghini saw their goals wrongly disallowed for offside in Italy's final group match, a 0–0 draw against Israel on 11 June. Following his disappointing and goalless performances in the group stage, and much media criticism and scrutiny, Riva finally opened his account in the World Cup in the second round. On 14 June, he helped Italy defeat the hosts Mexico 4–1 in the quarter-finals, scoring two goals, both from Gianni Rivera assists, forming a notable offensive partnership with the Milan playmaker in the knock-out rounds of the competition. Riva subsequently netted a crucial extra-time goal – his 22nd in 21 international appearances – against West Germany in Italy's 4–3 semi-final victory on 17 June, which is colloquially known as the "Game of the Century". The Italian team finished runners up in the tournament after losing 4–1 to Brazil in the final; Riva finished the competition as Italy's top-scorer, with three goals. After the tournament, Riva broke his right leg while on international duty in a European qualifying match later that year; he was forced off in the 76th minute of a 2–1 away win against Austria on 31 October, at the Praterstadion, in Vienna, following a hard challenge from Austrian defender Norbert Hof.