Juventus pounced on a costly blunder by Roma earlier Sunday to close the gap on the Serie A leaders to just one point after turning on the style to rout fellow title challengers Napoli 3-0 in Turin.
League newcomers Sassuolo stunned Roma at the Olympic Stadium by levelling in second-half injury time for a 1-1 draw to leave Rudi Garcia's leaders with just a four-point lead ahead of the top-of-the-table clash in Turin.
It gave both sides incentive, but Juve seized on home advantage to produce a dominant display and claim their 10th win of the campaign.
Spain striker Fernando Llorente tapped home for Juve in the second minute in somewhat controversial fashion and from then on Napoli struggled to find any rhythm.
Juve missed several clear chances but made the difference in six second-half minutes when Andrea Pirlo curled a free kick past Pepe Reina and Paul Pogba beat the keeper with a stunning volley from at least 20 metres out 10 minutes from the whistle.
Roma, who set a Serie A record of 10 successive opening wins two weeks ago, now lead Juve by just one point with Napoli dropping one place to third a further three points off the pace.
Inter Milan, 2-0 winners over Livorno on Saturday, remain in fourth with a one-point lead on Fiorentina, who got back on track with a shaky 2-1 home win over Sampdoria thanks to a double from Giuseppe Rossi which took his league-leading tally to 11 from 12 games.
In Turin, Reina was made to work throughout, but especially in a first half completely bossed by Juve, the keeper clawing away a Pogba effort after just 40 seconds.
Juve were in front barely a minute later when Llorente tapped home a loose ball following Carlos Tevez's backheel flick although replays suggested he was marginally offside.
Reina then produced a spectacular diving save to keep out a header from Leonardo Bonucci, while Napoli spurned their best chance until then when Gonzalo Higuain collected Pablo Armero's cross from the left and held off Angelo Ogbonna to turn and send his drive just wide of Gianluigi Buffon's upright.
Tevez was given time and space just outside the area to hit a strike that Reina parried without too much trouble and Reina was then relieved when Kwadwo Asamoah ran on to Pogba's pass to skew his effort into the side netting.
Lorenzo Insigne grabbed a rare opportunity for Napoli but saw his dipping drive sail just over the hands of Buffon after he turned inside from the left flank.
Napoli started the second half positively but failed to really threaten Buffon.
Insigne won a free kick on the corner of the area after Bonucci's late challenge and the diminutive winger's curling effort forced the Juve 'keeper to dive smartly to his right and parry.
Marek Hamsik almost made amends for a caution following a clumsy tangle with Pirlo, but sent his angled drive into the side netting while in a good position.
At the other end Arturo Vidal spurned a golden chance to double Juve's lead when he too hit the side netting after being sent through by Mauricio Isla.
The match turned decidedly in Juve's favour when Reina could only watch as Pirlo's free kick landed in his top right-hand corner on 74 minutes.
Pogba put the icing on the cake with a superb volley which went in off Reina's post on 80 minutes.
Although Juve finished the match with 10 men following Ogbonna's sending-off for a second caution three minutes later, the damage had already been done.