[1][2] His performances and prolific goalscoring attracted the attention of Serie A club Milan, by whom he was subsequently acquired in 1991;[2] however, he often struggled to find space in the team's starting XI under manager Fabio Capello, due to the presence of established forwards such as Marco van Basten and Ruud Gullit; he obtained only three league appearances, making his club and Serie A debut on 15 September 1991, in a 1–1 away draw against Juventus in Turin, as Milan finished the 1991–92 season as Serie A champions.
[1][3] The following season, Cornacchini returned to Serie C1, joining Perugia, where he scored 59 goals over three seasons, finishing as the top scorer of his division in the first two, and later helping his team achieve promotion to Serie B as the league's second-highest goalscorer, behind only Giovanni Pisano.
Notwithstanding this, the following season, he was acquired by Vicenza manager Francesco Guidolin (whom he later described as his best manager in 2019),[4] where he won the 1996–97 Coppa Italia,[1][5] contributing to his team's victory by scoring important goals in the competition,[6] in particular against Genoa, and later against his former club Bologna in the semi-finals;[1][7] he also started in the victorious two-legged final against Napoli.
[1][12] A fast, agile, and diminutive forward, Cornacchini was known for his speed in tight spaces, his opportunism inside the penalty area, and his eye for goal; however, he was not particularly skilful from a technical standpoint.
Despite his slender build and small stature of 1.69 m (5 ft 6+1⁄2 in), he was also effective in the air, courtesy of his power and elevation.