Mario Mandzukic scored the only goal for Juventus to dump further hurt on crisis club Roma and keep the champions unbeaten and on track for an eighth straight Italian league title.
The World Cup runner-up headed in the winner 34 minutes into the match in Turin to put Juventus back eight points clear of Napoli.
The defeat could have been harsher but for Roma goalkeeper Robin Olsen denying Cristiano Ronaldo, with Douglas Costa having a late goal ruled out following a video assistant referee check because of a foul in the build-up.
"We are doing good things, we have reached the Champions League last sixteen and we're winter champions," said coach Massimiliano Allegri, referring to the name given to teams top before Christmas.
Serie A is however holding a round of fixtures on December 26 and 29, before pausing for three weeks.
"We haven't won anything yet," added Allegri. "The important thing is to be a few ahead of Napoli on the 29th of December."
Roma, after finishing third last season, are now 25 points behind Juventus and drop to 10th after their eighth defeat in as many trips to the Allianz Stadium. They have won just twice in the league since the end of September.
Napoli are way behind Juve but consolidated second place when Raul Albiol headed his first goal of the season from a Dries Mertens corner against to beat struggling SPAL.
"Thinking of Juventus is likely to demotivate us," said coach Carlo Ancelotti.
"We have to think about ourselves because this team can do more, we have room for improvement and I say it after today's match, which was not amazing."
Inter Milan were held 1-1 at bottom club Chievo to fall eight points behind Napoli. Meanwhile, the pressure is on Milan coach Gennaro Gattuso after Federico Chiesa's second-half scorcher pushed AC Milan out of the Champions League places at the expense of Lazio.
"There's no use looking at who's to blame. The team is going through a bad moment," said Gattuso, whose side have take just two points from their last three games.