Luka Modric struck as Milan won 1-0 on the day at San Siro stadium.
Allegri later said: : "The team played a good game, we defended as a team and conceded little to nothing. We could have made better use of the chances we created, but the most important thing is our spirit.
"We're improving our defense, everyone is paying more attention. We also have the quality up front to create chances."
Alexis Saelemaekers created the winner and Allegri continued: "I have to congratulate Saelemaekers, who played a great match even after being booked. He can become even stronger. (Fikayo) Tomori also did very well, as did the whole team."
On Ruben Loftus-Cheek's performance, he added: "He had a good game. He's improving, and when he gets going in open play he's devastating."