Stephan Lichtsteiner, Giorgio Chiellini and Arturo Vidal scored for the hosts, while Rolando netted a consolation for Walter Mazzarri's men
The champions' 12-game winning run in the league was ended when they were held at Lazio last weekend, but normal service was resumed as they maintained their 100 per cent record at Juventus Stadium in the Italian top flight.
Stephan Lichtsteiner opened the scoring in the first half and fellow defender Giorgio Chiellini doubled Juve's lead just after the break as Inter were made to pay for some awful defending.
The visitors' team coach was pelted by stones on the way to the ground and their miserable day continued as Arturo Vidal made the most of some more terrible defending to add a third goal. Rolando pulled one back for Inter, but it was too little, too late.
With Roma's clash against Parma earlier on Sunday abandoned due to a waterlogged pitch, Antonio Conte's side were able to increase their advantage at the summit.
Inter, on the other hand, are without a win in six games in all competitions and now sit sixth.
New signing Pablo Daniel Osvaldo was not deemed fit enough to make his Juve debut, but Andrea Pirlo was restored to the starting line-up. Marco Storari replaced the suspended Gianluigi Buffon in goal and defender Chiellini returned from his ban.
The formalities for Hernanes' move from Lazio were not completed in time for the midfielder to make his Inter bow, but Danilo D'Ambrosio - another new recruit - was among the substitutes.
Juve should have taken the lead inside the opening two minutes, but Carlos Tevez spurned the opportunity to end his five-game goal drought.
Inter were caught napping when Paul Pogba headed the ball into the penalty area and Samir Handanovic came to their rescue by somehow keeping out Tevez's left-foot volley and then bravely denying the Argentina striker following up.
The home side were in front just 15 minutes in, though, as Pirlo picked out Lichtsteiner and the unmarked defender guided a header into the far corner.
Inter missed a glorious chance to level before the break when Rodrigo Palacio fired over the crossbar following a swift counter-attack.
Conte's charges gave themselves breathing space just two minutes into the second half when the impressive Pogba headed on and Chiellini capitalised on some hesitant defending to fire home with his right foot from close range.
Palacio's frustration continued when he blazed over the bar and he was again made to pay when more dreadful defending resulted in Vidal finishing with his left foot after the busy Handanovic had kept out Pogba's effort 10 minutes into the second half.
D'Ambrosio came on to make his debut three minutes later and Rolando pulled a goal back with a strike through a crowded penalty area 18 minutes from time.
Palacio still had time to waste another chance, heading over despite being unmarked, and Conte brought Mirko Vucinic on to face the club he looked set to join in a swap deal with Fredy Guarin, with the striker forcing a finger-tip save from Handanovic as Juve secured another win.