Inter beat bitter rivals AC Milan 3-2 in Sunday's thrilling derby to move above their neighbours in the Serie A table, with Lautaro Martinez's penalty ultimately proving decisive.
Luciano Spalletti, who was sent to the stands in the closing stages, had seen his side win just once in five competitive outings amid the ongoing stand-off with Mauro Icardi, but they produced a focused display to end Milan's five-match winning Serie A streak.
Inter were superior to Milan all over the pitch in the first half, with Matias Vecino's early goal setting the tone for proceedings until the break, before Stefan de Vrij made it 2-0 just after the interval.
Tiemoue Bakayoko hit back for Milan before Martinez – who continues to start in Icardi's place – netted from the spot and, although Mateo Musacchio forced a tense finish, Inter just about did enough to move back up to third above their rivals.
Despite Milan's excellent form coming into the game, Inter looked far more fired up at the start and went ahead after just three minutes – Vecino blasting in from close range after Martinez nodded Ivan Perisic's cross back into the danger zone.
De Vrij doubled the lead in the 50th minute when he met Matteo Politano's cross with a towering header into the top-right corner.
But the deficit was halved soon after – Bakayoko meeting Hakan Calhanoglu's free-kick with a fine header of his own.
The lively Politano won a penalty from Alessio Romagnoli in the 67th minute, with Martinez confidently dispatching what proved to be the clincher.
Musacchio thrashed home from six yards soon after – the goal standing despite Krzysztof Piatek appearing to stray offside.
Milan were boosted again when VAR overturned a red card shown to Andrea Conti for a rash tackle on Martinez, the reversal sparking a reaction from Spalletti which brought about his dismissal.
But Inter managed to hang on, with Samir Handanovic crucially blocking Samu Castillejo's late header and Danilo D'Ambrosio brilliantly denied Patrick Cutrone.
What does it mean? Derby della Madonnina still a spectacle
It is fair to say that neither Inter nor Milan are what they once were, but on Sunday they put on quite the show, scrapping like their lives depended on it and also producing a bit of quality now and again. These are not classic squads, but the derby remains a rollercoaster ride.
Martinez holds his nerve
Although chances for the Argentinian striker were not frequent, Martinez ran tirelessly, kept the Milan defence busy and showed admirable nerve to score his penalty. The youngster looks at home in this fixture.
Piatek fails to shine in the spotlight
With Icardi absent, the opportunity was there for Piatek to show who is the new star in town, but he offered precious little for a Milan side who rarely threatened aside from their two goals.
Milan travel to Sampdoria on Saturday, while Inter host Lazio a day later.