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Costacurta won 5 Champions League/European Cup trophies during his illustrious career as a defender for AC Milan. He was an integral part of the legendary Milan team of the late 1980s and 1990s, which dominated European football and won numerous titles, including the Champions League in 1989, 1990, 1994, 1995, and 2003. Costacurta's defensive prowess and leadership played a crucial role in Milan's success during that era.