Scott McTominay made sure that Napoli will stay top of Serie A for at least another week with the only goal in Sunday's 1-0 win at Torino while challengers Lazio fell to a 3-1 defeat at Parma.
Napoli are provisionally four points ahead of the chasing pack thanks to McTominay's neat finish in the 31st minute following a trademark dribble into the area from Khivcha Kvaratskhelia.
McTominay's winner was his third Serie A goal since signing for Napoli in the summer and the Scotland midfielder is playing a key role in his new team's bid for a fourth Italian league title.
Napoli would have left Turin with a heftier goal haul had Torino goalkeeper Vanja Milinkovic-Savic not pulled off a series of top class saves.
The Serbia 'keeper kept out a Romelu Lukaku backheel and Kvaratskhelia's looping header before McTominay broke the deadlock, and he got down brilliantly to stop both Matias Olivera's close range header in the 65th minute and Giovanni Simeone in stoppage time.
Two of the teams who trail Napoli by four -- champions Inter Milan and high-flying Fiorentina -- face off in Florence later on Sunday.
Lazio have lost ground after a frustrating defeat at Parma which was inflicted by an early Denis Man finish, teenager Anas Haj Mohamed's first Serie A goal and a stoppage-time strike from Enrico Delprato after Valentin Castellanos had halved the deficit for the away side.
Marco Baroni's fifth-placed side, who are level on 28 points with Inter, Fiorentina and Atalanta, thought they had taken the lead in the second minute through Nicolo Rovella before the strike was ruled out for a foul by the Italy midfielder.
Rovella then handed Parma the lead when he rolled a sloppy pass across his own area stright to Man, who gobbled up the chance to net his fourth goal of the season.
Castellanos then had a goal chalked off for offside before Lazio were awarded, and then denied via a VAR check, a penalty on the stroke of half-time.
Lazio came out on the front foot after the break but Haj Mohamed's beautiful curling effort -- his first Serie A goal in his first start in Italy's top flight -- doubled the hosts lead.
Castellanos' goal was followed by intense pressure from Lazio but Delprato ensured that Parma would move up to 11th, four points above the relegation zone, after being sent clean through by Gabriel Charpentier.
Patrick Vieira won his first match as Genoa coach with a 2-0 success at 10-man Udinese which moved his new team three points away from the Serie A relegation zone.
Genoa are 14th on 14 points thanks to Andrea Pinamonti's early close range finish and Lautaro Giannetti's 67th-minute own goal.
Vieira, who replaced sacked Alberto Gilardino during last month's international break, was helped by Isaak Toure being sent off for elbowing Alessandro Zanoli with barely a minute gone.
Udinese are ninth on 17 points but are on a worrying run of form, with Sunday's defeat the fourth in a five-match winless run for Kosta Runjaic's team.
Sixth-placed Juventus finish the day's action with a home clash at struggling Lecce.