Diego Moreira was the standout performer at San Siro, scoring once and providing two assists as Milan secured their fourth consecutive victory over Inter across all competitions.
The Rossoneri made a flying start and needed only four minutes to take the lead. Moreira created space on the right before delivering an excellent cross into the penalty area, where Christian Pulisic rose to head past Inter goalkeeper Josep Martínez.
Milan doubled their advantage in the 10th minute through Adrien Rabiot. Moreira delivered a low corner into the midfielder’s path, and Rabiot produced a clever finish that went in off the post.
Inter responded and gradually found their rhythm after the difficult opening spell. Their pressure paid off in the 22nd minute when Alessandro Bastoni headed home from close range following a corner delivered by Hakan Çalhanoğlu and flicked on by Manuel Akanji.
The Nerazzurri pushed for an equaliser, but goalkeeper Mike Maignan produced several important saves to preserve Milan’s advantage.
Moreira then delivered another moment of quality shortly before half-time. The Belgian winger stepped up to take a free-kick in the 43rd minute and curled a superb effort over the defensive wall and beyond Martínez to restore Milan’s two-goal cushion.
The hosts went into the break with a 3-1 advantage.
Milan withstand Inter’s second-half pressure
Inter attempted to revive their comeback hopes after the restart, with Carlos Augusto missing a good opportunity and Nicolò Barella seeing his effort blocked by Milan’s defence.
The visitors thought they had a chance to reduce the deficit further when referee Marco Guida initially awarded a penalty following an apparent handball by Mario Gila.
However, a VAR review overturned the decision after replays showed that the ball had struck Gila’s body rather than his hand.
Milan remained organised defensively, while Maignan continued to frustrate Inter’s attacking players.
Despite making several substitutions, Inter struggled to find a way through, and Milan comfortably protected their two-goal advantage until the final whistle.
Moreira leads Milan’s derby triumph
Moreira's contribution was central to the victory. The 22-year-old created both of Milan's opening goals before producing a spectacular free-kick to complete his personal performance with a goal and two assists.
Pulisic also continued his impressive record in the derby, scoring his fourth goal against Inter. The American had signed a new contract with Milan extending his stay until 2031 shortly before the encounter.
Rabiot's goal further underlined his importance to the team, while Maignan's saves ensured that Inter could not turn their second-half pressure into a comeback.
What the result means
The victory moved Milan to 21 points from 10 Serie A matches, placing them fourth at the time of the result and four points behind joint leaders Inter and Lazio.
Inter, meanwhile, suffered their first league defeat of the campaign, giving Lazio an opportunity to move clear at the top when they face Cagliari.
The result also extended Milan's unbeaten run against Inter to eight meetings across all competitions, with the Rossoneri recording their fourth consecutive derby victory.
Milan will now turn their attention to their UEFA Europa League fixture against Ferencváros on Thursday, 5 November, while Inter will look to respond when they return to league action.
Full-time: AC Milan 3-1 Inter Milan
Goals:
• AC Milan: Christian Pulisic 4', Adrien Rabiot 10', Diego Moreira 43'
• Inter Milan: Alessandro Bastoni 22'