Carlo Ancelotti's Napoli are second, eight points behind the seven-time reigning champions, after seeing off struggling SPAL 1-0.
But Inter Milan are now eight points adrift of Napoli, who they play on December 26, after being held late 1-1 at bottom club Chievo, with city rivals AC Milan dropping out of the Champions League places, with a 1-0 defeat to Fiorentina.
Here are five things we learned from Serie A this weekend:
Ronaldo ready for a rest
Cristiano Ronaldo could rest for the first time since his 100 million-euro ($117 million) move from Real Madrid last summer in next Wednesday's game at Atalanta, coach Massimiliano Allegri said.
The 33-year-old has started every one of Juve's 17 league games, scoring 11 goals, being substituted just once, in the final 10 minutes against Fiorentina this month after he scored the third goal from the spot.
"Cristiano Ronaldo had several chances today and happened to come up against a goalkeeper having a stunning performance. He may well rest in the next match," said Allegri.
Ghosts of past haunt Roma
Roma coach Eusebio Di Francesco conceded his side lived in fear of past defeats as they fell to an eighth consecutive loss to Juventus at the Allianz Stadium in Turin.
"The team lived the fears of previous games, playing with little certainty," said Di Francesco as Roma, who finished third last season, slipped to 25 points behind the leaders.
"In the second half we let ourselves go, accepting more duels, were better at managing the ball.
"The maturity of Juventus is superior, but I'm happy with Roma's reaction," added the Roma coach.
Despite being 10th in Serie A, Roma are just four points behind Lazio, who occupy the final Champions League spot.
Inter reel at Chievo leveller
Luciano Spalletti said he was shocked as Inter Milan allowed bottom club Chievo to snatch a point.
Chievo's veteran captain Sergio Pellissier struck with a lob in stoppages to cancel out Ivan Perisic's opener.
"We had so many chances to kill off the game and didn't take them," said Spalletti, whose side also crashed out of the Champions League this month.
"Right at the end, this hole in the defence opened up and Pellissier took full advantage. It's not a physical issue of slowing down towards the end, it's purely a psychological one."
Unhappy Higuain may be on the move
Speculation that Gonzalo Higuain could make a January move were fuelled after coach AC Milan coach Gennaro Gattuso said the Argentine forward was growing increasingly frustrated.
"No striker is happy when he does not score, but it's also hard for the whole team," said Gattuso, whose side have won just one of their last six league games.
There have been reports Higuain could be exchanged with Chelsea's Alvaro Morata.
"The winter market? It's a question that must be asked of management. Higuain is going through a difficult moment, like the team and as long as he is here he remains an important player to be exploited to the full," Gattuso added.
Higuain scored 16 goals last season for Juventus before joining Milan on loan. The 31-year-old has scored five this term, but none since October 28.
Lucky 13: Piatek tops goal chart
Krzysztof Piatek extended his lead at the top of the Serie A scoring charts when he scored his 13th goal of the season in Genoa's 3-1 win over Atalanta, the Polish striker moving two ahead of Juve's Cristiano Ronaldo after sealing the points two minutes from the end.
City rival Sampdoria's fellow on-fire striker Fabio Quagliarella scored his eighth goal in seven league games as the Genoa club beat Empoli 4-2, taking his tally for this season to 10.