The 1988–89 season would see Costacurta gain more playing opportunities and appear more frequently for the club, as he would feature in Milan's 3–1 win over Sampdoria in the 1988 Supercoppa Italiana. He would make 26 appearances in Serie A that season, and would also win his first European Cup title after Milan defeated Steaua București 4–0 at the Camp Nou, Barcelona. Costacurta played the first 74 minutes of the final before being substituted by Filippo Galli.