Juve, Napoli close gap on Roma
Juventus' goalkeeper Gianluigi Buffon (R) celebrates with Juventus' defender Giorgio Chiellini during the Italian serie A football match Juventus vs Catania on October 30, 2013 in Juventus stadium
Roma, who set an all-time league record last week by winning all nine of their opening games, will aim to make it 10 in a row on Thursday when they host bottom side Chievo Verona at the Olympic Stadium.
Chievo, who have four points and one win to their name all season, are set to become the latest victims of a rampant Roma side that has already accounted for Inter Milan, Napoli and Lazio.
Juventus and Napoli, however, avoided any slip-ups to keep pace with Rudi Garcia's record-setting side.
Champions Juve were in imperious form in Turin where Chilean midfielder Arturo Vidal started the rout with a deflected 28th minute strike, before Andrea Pirlo doubled the lead with a sumptuous curling free kick.
Carlos Tevez made it 3-0 just after the hour mark and Antonio Conte's side wrapped up the points when Leonardo Bonucci was allowed to run in unchallenged and tap home Sebastian Giovinco's low pass.
Away to Fiorentina, who stunned Juve with a come-from-behind 4-2 win two weeks ago, Napoli were expected to work hard for the points.
However, Rafael Benitez's men were never under pressure, typified by a 12th minute opener after Gonazalo Higuain crossed to the right for Spaniard Jose Callejon to beat goalkeeper Neto with a sweetly-struck first-time strike.
Fiorentina were soon back on level terms when Giuseppe Rossi's spot kick, after Borja Valero was fouled in the area, sent Pepe Reina the wrong way.
It took Rossi's league-leading tally to nine goals, but his and Fiorentina's joy was short-lived. Napoli restored their advantage on 36 mintes when Dries Mertens ran unchallenged into the hosts' area to beat Neto with an angled strike.
Fiorentina spurned several chances to pull level in the second half, Rossi sending his shot from a difficult angle wide of goal and then his curling effort bring a great diving save from Reina.
Napoli midfielder Christian Maggio saw red on 80 minutes for a second bookable offence, but as Fiorentina battled for the equaliser, they were also reduced to 10 men when Juan Cuadrado was sent off in injury time for simulation after tumbling in the area under a challenge from Gokhan Inler.
With league new boys Verona securing a precious 2-0 home win over struggling Sampdoria, Fiorentina's second reverse dropped them one place to sixth, nine points adrift of Roma and seven behind Napoli and Juventus.
With coach Massimiliano Allegri under incrdeasing pressure, AC Milan were desperate for all three points at home to Lazio and were sent on their way when Kaka scored a sublime individual goal just after the restart.
The hosts, however, were stunned when French defender Michael Ciani fired home the equaliser on 72 minutes.
Miroslav Klose then missed a chance to wrap up the points for the visitors after he shot straight at Milan 'keeper Gabriel following a counter-attack launched by impressive Nigerian Ogenyi Onazi.
Elsewhere, Bologna claimed their second win of the season, a 3-0 away rout of Cagliari, to pull three points clear of the relegation zone.
A sublime Luis Muriel strike secured the points for Udinese in a 2-1 away win at Sassuolo while an Alessio Cerci penalty in the 87th minute clinched a 3-3 draw for Torino away to Livorno.