In 1975, Penzo was transferred to newly promoted Serie B side Piacenza in a co-ownsership deal. He struggled to fit into manager Giovan Battista Fabbri's system, however, and after three months, having failed to score and having made only two appearances as a substitute for the club, he was transferred to Serie C side Benevento, where he scored 12 league goals in 27 appearances during the 1975–76 season. The following season, he moved to Serie C side Bari, helping the club obtain promotion to Serie B with his prolific goalscoring, totalling 27 goals across his two seasons in Serie C. After another season in Serie B with Monza, he was sold to Brescia in 1979, helping the club achieve promotion to Serie A with 12 goals; the following season however, he struggled to find the back of the net, scoring only 4 times in 27 appearances, as Brescia suffered relegation at the end of the season.