Inter Milan leapfrogged AC Milan into third place in the Serie A table after claiming a 3-2 victory in the Milan derby.
Inter took the lead in the third minute when Matias Vecino stabbed home from close range after the ball had been headed into his path.
Goalkeeper Samir Handanovic produced good saves to deny AC Milan duo Lucas Paqueta and Hakan Calhanoglu before Milan Skriniar headed narrowly wide for Inter as the first half neared its conclusion.
Stefan De Vrij doubled Inter's lead six minutes into the second period when he headed in from 12 yards but Chelsea loanee Tiemoue Bakayoko pulled a goal back for Milan six minutes later.
Lautaro Martinez restored Inter's two-goal advantage from the penalty spot in the 67th minute after Matteo Politano had been brought down.
Milan then reduced the deficit for a second time four minutes later, with Mateo Musacchio slamming in from a few yards out.
AC Milan substitute Andrea Conti was initially shown a red card for a foul on Martinez in the 87th minute but that was downgraded to a yellow following a VAR review.
Danilo D'Ambrosio produced a sensational block to keep Patrick Cutrone's effort out in added time as Inter held on to take all three points.
Juventus suffered their first league defeat of the season as Genoa made the most of Cristiano Ronaldo's absence to win 2-0 at the Stadio Luigi Ferraris.
Top-scorer Ronaldo was not in the matchday squad as runaway leaders Juve were seen off by second-half goals from their former midfielder Stefano Sturaro and veteran forward Goran Pandev.
Second-placed Napoli moved to within 15 points of Juve after a second-half rally helped them to a 4-2 win against Udinese.
Napoli found themselves 2-0 up after 26 minutes when Jose Callejon added to Amin Younes' earlier curling effort.
But Udinese fought back, with goals from Kevin Lasagna and Seko Fofana pulling them level before Napoli goalkeeper David Ospina had to be taken off in the 44th minute after collapsing following an earlier head injury.
Second-half goals from Arkadiusz Milik and Dries Mertens secured the points for Napoli.
Four first-half goals lifted Lazio to an emphatic 4-1 victory over Parma.
Adam Marusic set the ball rolling in the 22nd minute before Luis Alberto scored from the penalty spot four minutes later.
Luis Alberto got his second and Lazio's third in the 38th minute before Senad Lulic made it 4-0 from a well-worked corner routine on the brink of half-time.
Mattia Sprocati scored a consolation goal for Parma 13 minutes from time.
Empoli recorded an important 2-1 victory over fellow relegation-battlers Frosinone.
Home forward Francesco Caputo broke the deadlock from the penalty spot before Marko Pajac made it 2-0 seven minutes before the break.
Luca Valzania's 70th-minute goal handed Frosinone a lifeline but Empoli held on to secure maximum points.
Josip Ilicic's second-half effort cancelled out Riccardo Meggiorini's opener as high-flying Atalanta drew 1-1 with basement club Chievo.