Giovanni Simeone, son of Atletico Madrid coach and former Argentina captain Diego, scored for the second game running to give Genoa a 1-0 win at Bologna in a game of three red cards.

Juve's win took the defending champions on to 18 points from seven games, four clear of Napoli with Lazio and Chievo a further point behind after their wins on Saturday.

Napoli had been in better form than Juventus recently and began confidently in Bergamo but were stunned when Andrea Petagna struck in the ninth minute.

The visitors, strangely ineffective in attack, could find no way back as they went down to their first defeat in their ninth competitive match of the season.

Juventus took more than an hour to break down their stubborn opponents, then scored three times in six minutes to claim their sixth win in seven league games.

Dybala made the breakthrough in the 65th minute and his fellow Argentine Higuain added two more, the second after an awful mistake by Empoli defender Marco Zambelli, to take his league tally to six.

"This squad has only been together really for 40 days, what with the various breaks for international duty," said coach Massimiliano Allegri. "Winning games is all that counts and the rest is just gossip."

Simeone nearly scored a sensational first-half goal at Bologna as he raced from inside his own half only to see his shot hit the foot of the post.

The 21-year-old, who scored his first Serie A goal the previous week against Pescara, was not to be denied however and got in front of his marker to turn in Diego Laxalt's cross in the 77th minute.

Bologna were already down to 10 men after captain Daniele Gastaldello was sent off two minutes before halftime.

Genoa had Santiago Gentiletti sent off for a second bookable offence in the 85th minute and Bologna finished with nine men when Blerim Dzemaili was dismissed for a clumsy foul.

There was a dramatic finish at Sampdoria where Bruno Fernandes volleyed home five minutes into stoppage time to give the hosts a 1-1 draw with Palermo. Basement club Crotone remained the only team without a win following a 2-1 defeat at Cagliari.