An enthralling weekend of Italian action ended with second-placed Juve prevailing in Turin thanks to defender Leonardo Bonucci using his knee to divert Mirko Vucinic's shot into the net after 54 minutes.
Arturo Vidal and Fabio Quagliarella ended Napoli's resolve.
After a shaky few weeks, Juve can again smell a first title since their 2006 match-fixing demotion after champions Milan drew 1-1 at Catania on Saturday amid more goal-line controversy when a Robinho effort was wrongly ruled not to have gone in.
Eight games remain in the best title-run many Italians can remember given the dominance of Inter Milan from 2007-2010.
Seventh-placed Inter reignited their outside hopes of reaching third spot after Diego Milito bagged a hat-trick in a 5-4 thriller at home to Genoa to boost ex-youth coach Stramaccioni, who took over from Claudio Ranieri last week.
BIG FAMILY
"Contrary to what is being said, coming from the youth sector, I've found a united Inter, a big family," Stramaccioni, in charge at least until the end of the season, told Mediaset.
"It was only Inter v Genoa, but it was important, so therefore it was lovely."
The hosts raced into a 3-0 lead with Argentine Milito scoring twice within the first half-hour and his countryman Walter Samuel sliding home Lucio's cross in the 38th minute.
Genoa refused to lie down and goals from Emiliano Moretti and Rodrigo Palacio gave 36-year-old Stramaccioni a fright.
A 74th-minute Mario Zarate goal looked to have sealed the win but a frantic final 10 minutes, in which three penalties were scored including Milito's third goal, almost led to a draw.
However, Inter ran out winners despite having goalkeeper Julio Cesar sent off in the 79th minute and are now seven points off third-placed Lazio, who occupy the Champions League qualifying round berth but went down 3-1 at struggling Parma on Saturday.
RAMPANT ROMA
Goals also flowed at the Stadio Olimpico where Roma thrashed second-bottom Novara 5-2 to move four behind city rivals Lazio.
The visitors had taken the lead through Andrea Caracciolo's deft header but Roma hit back when Marquinho equalised with his first goal for the club via a bullet header after 25 minutes.
The hosts went ahead nine minutes later when Osvaldo headed in Francesco Totti's corner and three second-half goals from Simplicio, Bojan Krkic and Eric Lamela sealed the win with Takayuki Morimoto scoring for Novara.
Roma remain sixth but are now only a point behind Napoli and Udinese, whose poor form continued with a 1-0 loss at Siena.
Fiorentina's recent slump went on as they lost 2-1 at home to Chievo, leaving them in
