Napoli matched Juventus with a 1-0 win over SPAL on Sunday to regain top spot in Italy from the champions who had earlier won the Turin derby by the same score.
The two Serie A pacesetters both bounced back from European setbacks to claim their ninth consecutive league wins.
Napoli -- shocked 3-1 at home by RB Leipzig in the Europa League -- stayed top with a narrow home victory at their San Paulo Stadium and injury-depleted Juventus -- held at home by Tottenham in the Champions League -- continued their derby domination of Torino 1-0.
"I expected a response after the Europa League," said Napoli coach Maurizio Sarri, but added his side should have scored more.
"We became too lazy and wanted to walk the ball into the net. We were acting 10 minutes from time as if we were 3-0 up, not 1-0."
Both clubs could thank Brazilians for the three points with Alex Sandro scoring for Juventus after 33 minutes and Allan putting Napoli ahead after just six minutes.
Napoli have 66 points after 25 games with Juventus one point behind. AS Roma moved third 15 points behind the top two with a 2-0 win at Udinese Saturday as Inter Milan fell back into crisis with a 2-0 loss in Genoa.
Luciano Spalletti's side are now fourth and could fall to fifth if Lazio beat Verona on Monday.
In Naples, Lorenzo Insigne hit the post after four minutes before Allan broke through after good work by Jorginho and Jose Callejon.
Marek Hamsik thought he had scored a second after 63 minutes but the video assistant referee (VAR) ruled he was offside.
It was a new club record of nine consecutive league wins for Napoli.
"This team appears to only have Serie A in its mind and has no motivation for anything else," added the Napoli coach of his side's bid for a third Serie A title and first since 1990.
- Higuain, Bernardeschi injury blow -
In Turin, Juventus top scorer Gonzalo Higuain suffered a sprained ankle while winger Federico Bernardeschi injured his left knee in the bruising 'Derby Della Mole'.
Higuain has scored 24 times this season for the champions including a double in the first nine minutes of last Tuesday's Champions League game in Turin.
The 30-year-old pulled up in agony three minutes into the game at Torino following a clash with rival goalkeeper Salvatore Sirigu.
He continued on for another 12 minutes before being replaced by Bernardeschi, who set up Brazilian Alex Sandro to score 20 minutes later, before limping off late in the second half.
Both will be racing to be fit for the Champions League return leg at Wembley on March 7.
Juventus already have a long injury list with Mario Mandzukic, Blaise Matuidi and Juan Cuadrado recovering but Argentine Paulo Dybala returned from a hamstring injury in the second half.
"Dybala did well for 30 minutes, obviously he's lacking match fitness, but that will come," said coach Massimiliano Allegri.
"I am proud of the lads and today we saw a good reaction, as we enjoyed ourselves even during difficult moments."
Torino are ninth five points off the European places.
- Gattuso 'spark' fires Milan
In the battle for Europe, Giacomo Bonaventura scored on 14 minutes as AC Milan continued their revival under Gennaro Gattuso, beating Sampdoria 1-0 to pull level with the side from Genoa in sixth with 41 points.
Gattuso extended his unbeaten run to ten games following last week's 3-0 win away to Ludogorets in the Europa League.
Sampdoria goalkeeper Emiliano Viviano saved a Ricardo Rodriguez spot kick, with Leonardo Bonucci's second for the hosts ruled offside.
"The credit goes to the lads, as they just needed a spark to fire them up," said Gattuso.
"We can enjoy the moment but nothing has been achieved yet. We've left many points on the road and have to work."
Just behind Milan, Atalanta were held 1-1 by Fiorentina with tailenders Benevento snatched their third win 3-2 against Crotone with a last-gasp goal from new signing Cheick Diabate.