In front of the club's new owners, Rafael Leao has inspired AC Milan to a 3-2 victory over fierce rivals Inter in a fiery Serie A city derby.
Leao had a hand in all three Milan goals on Saturday, scoring two and setting up the other for Olivier Giroud.
Marcelo Brozovic gave Inter the lead in the 21st minute and Edin Dzeko pulled one back for the Nerazzurri in the 67th.
"In order to improve, you need talent and intelligence. Rafa has talent and he is a very intelligent guy," Milan coach Stefano Pioli said about Leao.
"You need to give youngsters the time to grow and the freedom to make mistakes. We try to put him in the best conditions: he's one of our weapons, not the only one, but an important one ... Rafa is someone who understands, listens, and knows that he must never be satisfied. He knows that with this talent he can aim for the skies.
"It was an important match ... I am really a happy manager."
Defending Italian champions Milan moved to the top of the standings and were joined later by Napoli after winning 2-1 at Lazio, who fell to their first defeat.
Napoli's new signings shone as Kim Min-jae and Kvicha Kvaratskhelia cancelled out Mattia Zaccagni's early opener in Rome.
Elsewhere, there was more disappointment for Juventus as they didn't even have a shot on target in the second half in Florence, while new signing Leandro Paredes gave away a penalty in the 1-1 draw.
Fellow new signing Arkadiusz Milik put Juve ahead in the ninth minute with his second goal in as many matches.
Fiorentina equalised from a counterattack that was finished by Christian Kouame in the 29th.
Just before halftime, Fiorentina were awarded a penalty for a handball by Paredes. But Mattia Perin, standing in again for the injured Wojciech Szczesny, pushed Luka Jovic's spot kick onto the post.
Juventus goalkeepers have saved four of the last seven penalties they have faced in Serie A.