Gonzalo Higuain was mindful not to celebrate after hitting his seventh league goal of the season.
Gonzalo Higuain hit a fairytale winner as Juventus edged the Argentine's former club Napoli 2-1 in Turin on Saturday to stretch their lead to five points at the top of Italy's Serie A.
Higuain, who hit a Serie A record of 36 goals for Napoli last season, has become a hate figure at the San Paolo stadium after moving to Juventus for an Italian transfer record fee of 90m euros.
Although he can expect a red-hot welcome from Napoli fans, many of whom burned his shirt in disgust at his move, when the southerners host the champions on April 2, Higuain was mindful not to celebrate after hitting his seventh league goal of the season.
A superb volley by Leonardo Bonucci gave Juventus a 50th minute lead, only for Jose Callejon to beat Gianluigi Buffon four minutes later from Lorenzo Insigne's superb chip.
A tense and tactically-tight affair, which saw a number of clashes between players, looked to be heading for a 1-1 draw.
But when Higuain's cross for Sami Khedira spilled back into the striker's path, he made no mistake with a first-time drive that beat Pepe Reina down low on 70 minutes.
Juventus, aiming for a record sixth consecutive 'scudetto' this season, now have a five-point lead on Roma ahead of their visit to Empoli.
"It was important to win tonight," said Juventus coach Massimiliano Allegri.
"If we drew, Roma could have pulled level on points with us tomorrow. Instead, we won and now Napoli are seven points behind us. I think whoever came to see us tonight had a good time."
Napoli could drop to fourth if AC Milan account for lowly Pescara at the San Siro on Sunday.
But Napoli coach Maurizio Sarri insists they are Juve's real rivals: "We have faith in ourselves. We're Juve's key rivals, and people know it."
It took Juventus 12 minutes to fashion a decent chance but after breaking on the counter Higuain's lay-off to Mario Mandzukic had too much pace, and Reina had time to rush out and smother at the Croat's feet.
Higuain should have done better on 24 minutes later when he latched on to Sami Khedira's slide rule pass behind the Napoli defence, only to be thwarted by Vlad Chiriches's late challenge.
Napoli's slick passing game impressed, but without injured Polish striker Arkaduisz Milik, bought as Higuain's replacement from Ajax, the visitors lacked an aerial threat.
Sarri admitted Higuain's departure still hurt.
"We lost one of the best forwards in the world and the club made the decision to buy young players. I think the club made the right choice," he added.
When Brazilian midfielder Allan powered towards goal unchallenged, his tame drive from 25 yards gave Buffon no trouble.
Injury to Chiellini then prompted coach Massimiliano Allegri to introduce Juan Cuadrado shortly before the interval but the Colombian, who came off the bench to hit the winner in a 1-0 Champions League win at Lyon two weeks ago, was beaten to the opener.
A messy clearance by Faouzi Ghoulam following a corner caught Bonucci's attention and he turned quickly to smash a superb volley past Reina and into the roof of the net five minutes after the restart.
"This win is down to Juve never-say-die spirit. Tonight that's the attitude we had, after being without it at the San Siro (when Juve lost to AC Milan last week)," said Bonucci.
The match sprang into life and on a Napoli counter moments later Mertens narrowly failed to connect with Lorenzo Insigne's inswinger from the left.
From the corner, Ghoulam's delivery found Koulibaly at the far post but the Senegal defender's cross back towards goal was headed out by Mandzukic.
It was encouraging stuff from Napoli and they earned just rewards only two minutes later when a delightful Insigne chip found Callejon in behind the Juve defence.
The Spain international controlled perfectly and smashed a low drive under Buffon to pull the scores level on 54 minutes.
With seven goals in 11 appearances, it equalled his total league tally for last season.
Sarri replaced a tiring Insigne with Emanuele Giaccherini on the hour but it was Juve who struck next, Higuain driving his low drive through the legs of Chiriches to leave Reina, his former teammate, rooted to the spot.