Boninsegna was a member of the Italian side that reached the final of the 1970 FIFA World Cup in Mexico, scoring two goals throughout the tournament. In the epic semi-final match against West-Germany, he scored a goal, and later set up Gianni Rivera's match-winning goal in extra time, which allowed Italy to advance to the final after a 4–3 victory. He scored Italy's only goal (though at the time it was an important equaliser) in the final against Brazil, which Italy ultimately lost 4–1; he came off for Rivera in the final minutes of the game.