Juventus beat Inter in 'Derby of Italy'
With all the goals coming in the first half, Claudio Marchisio got the winner after Maicon's 28th-minute piledriver had cancelled out Mirko Vucinic's early strike.
The result leaves unbeaten Juventus two points clear of AC Milan ahead of Sunday's programme with a fifth defeat in nine games leaving struggling Inter fifth from bottom.
Champions AC Milan went second after Zlatan Ibrahimovic struck twice in a 3-2 win at Roma, while Catania moved to sixth with a 2-1 defeat of 10-man Napoli.
Juventus coach Antonio Conte said he was relieved his club still topped the standings.
"We are making big steps and it's very satisfying to come to the San Siro and win against a team who started the season as favourites," he told Sky Sports channel.
"It was a very intense game, our third game in a week, but we still need to improve and be a bit more clinical to finish off matches."
Inter coach Claudio Ranieri, who has now suffered three Serie A defeats since taking over from Gian Piero Gasperini in September, said he would not pay any attention to the table before adding: "We are not in the best shape physically while they are very fit... they scored with their only two chances."
Juventus struck first on 12 minutes as Vucinic slammed the ball high into the net after Luca Castellazzi had saved Alessandro Matri's close-range effort from Stephan Lichtsteiner's cross.
The dangerous Matri came close to doubling the lead twice in the next three minutes, flashing a cross-shot just wide of target before Castellazzi blocked another break from the Italian as Inter's defence was run ragged.
The home side weathered the storm and Maicon equalised on 28 minutes, surprising Buffon at the near post with an angled strike that took a slight deflection before flying into the top corner.
Galvanised by the goal, Pazzini thundered a header against the bar from Maicon's cross but it was Juventus who regained the lead on 33 minutes when the talented Marchisio hit a low shot into the corner after playing a delightful one-two with Matri on the edge of the box.
Inter pressed for an equaliser but with Dutch playmaker Wesley Sneijder strangely out of range, it was Juventus who created more openings.
Alessandro Del Piero, thrown on for the last few minutes, shot weakly wide after being sent clean through with four minutes to go but the 27-times champions kept the hosts at bay.
At the Stadio Olimpico, Ibrahimovic headed home Alberto Aquilani crosses in the 17th and 78th minutes as the Rossonero claimed their fourth successive win.
In an action packed opening period, Nicolas Burdisso had equalised for Roma on 28 minutes before Alessandro Nesta restored Milan's lead with a copycat header at a corner two minutes later. Bojan Krkic scored a 87th-minute consolation for the home side.
Milan coach Massimiliano Allegri, who was dismissed for using abusive language in the latter stages of the match along with Kevin-Prince Boateng, praised striker Ibrahimovic's contribution.
"Ibra was huge - he played a wonderful game as did [Christian] Abbiati," Allegri told Italy's Sky Sport channel. "It's an important win against one of the title challengers, and nice to savour victory at the place where we won the scudetto last season."
In Sicily, Napoli were beaten 2-1 at Catania with goals from Giovanni Marchese and Gonzalo Bergessio helping the hosts to a comeback win after Edinson Cavani's first-minute strike.