Costacurta began his final professional season with the club at age 40. During the season, he won his fifth UEFA Champions League title with Milan. On 7 May 2007, at age 41, he announced his retirement, effective at the end of the 2006–07 season. He remained with the club as a second assistant to manager Carlo Ancelotti for a short time afterwards. He made his final home start in Milan's 3–2 loss to Udinese on 19 May 2007, converting a penalty that marked his first Serie A goal since the 1991–92 season (15 years after his left-footed volley against Roma on 3 November 1991), and left the pitch near the end of the match to a standing ovation. With this goal, he became the oldest goalscorer in Serie A, at the age of 41 years and 25 days, surpassing the previous record held by Silvio Piola, who in Novara–Milan, on 7 February 1954, scored a goal at 40 years, six months and nine days. Costacurta also became the oldest outfield player to play in a Serie A match. The only players to have played in a match at a more senior age were goalkeepers Marco Ballotta (44 years and 38 days), Alberto Fontana (41 years and 297 days), Francesco Antonioli (41 years and 243 days) and Dino Zoff (41 years and 76 days). After the match, Costacurta's Milan teammates entered the pitch wearing a replica of his jersey as a tribute.