During the last matches of the 2009–10 season, Milito proved instrumental in Inter's winning of the first treble in the history of Italian football. The Argentine first scored the only goal in Inter's victory over Roma in the final of the Coppa Italia on 5 May 2010, enabling the "Nerazzurri" to take home their first trophy of the season. Eleven days later, it was also Milito's goal which secured Inter Milan's 18th "Scudetto" when they beat Siena 1–0 on the final matchday of Serie A. With only two points separating the top two teams in Serie A, the goal lifted Inter to the summit of the table after being in a position to lose the league title to Roma at the half-time break as Roma, playing simultaneously, were winning their own match against Chievo at that point. Milito himself declared this goal to be the "best of his career," having been decisive in delivering a league title to his team. On 22 May 2010, Milito yet again proved vital as he scored twice to seal a victory in the Champions League Final over Bayern Munich. As a result, Inter became European club champions for the first time in 45 years with a 2–0 victory and completed their historic treble championship season.