All three goals of the Serie A fixture were scored in the first half, with veteran striker Zlatan Ibrahimovic netting twice for the Rossoneri and Romelu Lukaku pulling one back for the Nerazzurri just minutes later.
Inter Milan had 19 shots on goal and were looking particularly dominant in the second half but only six of them were on target. The Nerazzurri had six players ruled out of the game after they tested positive for COVID-19, and their absence was felt on the pitch as Antonio Conte's men kept getting caught on the counter-attack.
AC Milan conceded their first goal of the season but were very organised at the back, especially after conceding a goal from Lukaku. Simon Kjaer also made a brilliant headed clearance from the goal-line to deny Lautaro Martinez.
It was Zlatan Ibrahimovic's night
Zlatan Ibrahimovic marked his return after recovering from COVID-19 in typical Zlatan fashion, scoring both the goals for AC Milan in just three minutes.
The 39-year-old played the entire 90 minutes of the game and was a constant threat for his side. He somehow managed to find space between the Inter defenders with his intelligent movements. He made the most of Aleksandar Kolarov's clumsy challenge to win and then score the penalty after Samir Handanovic dived to his right to make an impressive save, only for the Swede to slot home a left-footed rebound.
As AC Milan moved to the top of the Serie A standings with a fourth consecutive win, we take a look at the five talking points from the intense derby.
#5 Defence remains a concern for Antonio Conte
AC Milan were able to go two goals up within 16 minutes on Saturday and with that, Inter had conceded their seventh and eighth goal of the season in just four games. They finished the 2019-20 season with the best defensive record in Serie A. However, as things stand, they have the third-worst defensive record in the league.
They were missing their two key defenders in Alessandro Bastoni and Milan Skriniar so it was expected that their defence would be a bit sloppy. However, the ease with which Rafael Leão and Hakan Çalhanoğlu found spaces behind the defenders was concerning.
Antonio Conte has a lot of attack-minded defenders in his ranks and needs to develop a few of them as solid defenders so that they are not caught off-guard in the absence of their key centre-backs.
#4 AC Milan have found their rhythm
AC Milan became the only side in Serie A with a 100% win record after four games with their impressive 2-1 over Inter on Saturday. This victory marked their first win over their city rivals since 2017.
AC Milan have certainly started the season with a bang. Despite not being the highest-scoring team in the division, their defensive solidity and strength in the midfield have made the goals count.
There were lot of positives to take away from the game including their seamless transition from defence to attack and the great distribution shown from Hakan Çalhanoğlu in the final third.
AC Milan finally seem to have found their rhythm and have an easy set of fixtures ahead of them, which means they are likely to continue their unbeaten run in the near future.