Inter captured a third successive Derby della Madonnina victory against AC Milan on Saturday courtesy of a contentious Marcelo Brozovic goal shortly after the break and Romelu Lukaku's third for the club.
Milan's Hakan Calhanoglu was denied the opener in the 23rd minute after teammate Franck Kessie was adjudged to have handled the ball in the penalty area. Kessie was struck with a close-range attempted clearance by Inter's Kwadwo Asamoah.
Inter nearly scored 10 minutes before the interval when Danilo D'Ambrosio - who also rung the inside of the post in the 21st minute on a point-blank opportunity - struck a daring scissor-kick that was acrobatically palmed away by Gianluigi Donnarumma and into the path of Lautaro Martinez. However, the Inter forward was in an offside position when he fired the rebound into Milan's net.
Brozovic opened the scoring when his low free-kick deflected off Rafael Leao and beyond a helpless Donnarumma. The Milan 'keeper was one of several Rossoneri to protest the decision, citing the offside position of Martinez. Match official Daniele Doveri consulted with VAR before ruling the goal to be good.
Inter continued to turn up the pressure after the break. Defensively rigid under manager Antonio Conte, Inter stymied Milan's best efforts while looking the better side going forward. Lukaku then doubled the lead with a header from a Nico Barella cross in the 78th minute.
In the end, Inter were dominant, managing nine shots on target to Milan's one as Donnarumma repeatedly kept his side in a match that favored its San Siro co-dwellers.
With the 2-0 result, the Nerazzurri maintain a perfect start to the league campaign under Conte and reclaim top spot in Serie A ahead of Juventus.