Penzo's performances prompted the Turin club, for whom Platini coincidentally played, to purchase him from Verona the following season at the age of 30, in exchange for the co-ownership of Giuseppe Galderisi and Massimo Storgato; Penzo was initially intended to be a replacement for the recently departed Roberto Bettega, who had left Juventus to play football in Canada. Penzo immediately won the Serie A title, in what was to be his only season with the club, as his performances did not convince the Juventus management to renew his contract. Although he gelled well with his strike partner Paolo Rossi, his spell with Juventus was less successful than his time at Verona from an individual standpoint, however, as he was less consistent and was ultimately unable to replicate his goalscoring form from the previous season with the Turin side, only managing 5 league goals in 25 appearances, and often starting from the bench. Despite his struggles in front of goal in the league throughout the season, he starred for the club in the 1983–84 European Cup Winners' Cup, as Juventus also went on to win the competition that season; during the tournament, he achieved a rare feat of scoring 4 goals in the same game, which he managed in a 7–0 first round home win against Lechia Gdańsk on 14 September 1983. In total, he scored 10 goals in 36 appearances across all competitions for Juventus.