Monza coach Raffaele Palladino was delighted after victory at Inter Milan.
Luca Caldarola struck a second-half winner for the minnows.
Palladino later said: “It was an incredible feeling to come here and play against an Inter in good shape, that was highly-motivated and fresh from the Champions League, we played with great focus and made the most of the few chances we had. I am proud of these lads and told them we have written our names in history by winning at San Siro,.
“I can only thank the club that put its faith in me, the players and my staff. I thank everyone."
Monza GM Adriano Galliani, formerly of AC Milan, motivated the players with a speech before kickoff.
Palladino added: “Obviously, this was not a game like the others for him, he told me that he wanted to get a few points at San Siro in his old home. I often give the final speech to the team in the locker room, this time I wanted Galliani to do it, as nobody more than him could fire us up.
“We dedicate this win to him and above all to President Berlusconi."