Donnarumma pulled off a few big saves to keep his side in the match, but the Azzurri never really looked like scoring across the 90 minutes.
Relive how the match unfolded with Sports Mole's live text coverage below.
STARTING XI: Donnarumma; Lazzari, Caldara, Romagnoli, Criscito; Cristante, Jorginho, Bonaventura; Zaza, Immobile, Chiesa
SUBS: Sirigu, Perin, Emerson, Chiellini, Belotti, Insigne, Berardi, Benassi, Gagliardini, Bonucci, Bernardeschi, Barella
STARTING XI: Patricio; Cancelo, Pepe, Ruben Dias, Mario Rui; Pizzi, Ruben Neves, William Carvalho; Bruma, Andre Silva, Bernardo Silva
SUBS: Ramos, Beto, Neto, Mendes, Sanches, Oliveira, Bruno Fernandes, Guedes, Gelson Martins, Cedric, Gedson Fernandes
Fernando Santos: "Italy have enormous desire to show their value, having failed to qualify for the World Cup. Just because they were not present at the World Cup does not alter their history. This game is part of a new competition and naturally takes on another level of importance. It's hard to talk about favourites in games at this level, they are difficult for any of the teams."
Roberto Mancini: "They won the last European Cup. They are stronger when Ronaldo is playing. But even without Ronaldo the team is very good with lot of technical players. When Ronaldo will not play football anymore, I hope as far as possible for him, Portugal will try to do something different and this is a good chance for them. But they are still a great team, even without Ronaldo."
PORTUGAL SUBS: Ramos, Beto, Neto, Mendes, Sanches, Oliveira, Bruno Fernandes, Guedes, Gelson Martins, Cedric, Gedson Fernandes
ITALY SUBS: Sirigu, Perin, Emerson, Chiellini, Belotti, Insigne, Berardi, Benassi, Gagliardini, Bonucci, Bernardeschi, Barella