Rossi became an instant sensation and his 21 goals helped them to promotion and the club paid £1.500.000 to take him permanently. After being relegated, however, Lanerossi transferlisted him at £3.000.000, but he refused to join Napoli and went to Perugia on loan. It was a result of their game with Avellino in 1980 that he was accused of taking a bribe after the match ended 2-2 and Rossi scored both Perugia's goals. In 1981, whilst still suspended, Juventus bought him for £500.000. His suspension ended on April 29th 1982 and he was immediately recalled to international football in the 1982 World Cup.
The tournament started poorly for Italy. In a group with Peru, Poland and Cameroon, they only managed to score two goals. They went through on more goals scored than Cameroon. Not many fancied Italy to progress further when they ended up in the same group as Brazil and defending champions Argentina. A narrow 2-1 against Argentina gave sign of improvements. But Rossi still hadn't scored after 4 matches. Teamcoach Enzo Bearzot gave him a last chance to impress in the deciding match against Brazil. In a memorable game where Brazil only needed a draw to reach the semifinal, Rossi scored a magnificent hat-trick, and Italy won 3-2.
He continued to impress in the semifinal against Poland and scored both goals in the 2-0 victory, and in the final he scored the first in the 3-1 victory over West Germany. With that goal he also secured the topscorer title of the tournament.