Milan - Mauro Icardi hit his eighth goal of the campaign as Inter Milan edged "tough" Empoli 1-0 to reclaim top spot as a five-way race for the Serie A crown opened up.
Fiorentina had gone provisional top thanks to a 3-1 win at Palermo where Slovenia international Josip Ilicic notably struck a brace to take his goals tally to the season to nine in 18 games.
But Inter, one of several teams showing they have the tools to unseat four-time consecutive champions Juventus this season, restored their one-point lead thanks to Icardi's winner on the stroke of half-time.
It was the ninth time this season Inter have won 1-0, but that statistic is unlikely to unnerve coach Roberto Mancini as long as his side keep on winning.
"Empoli are a really tough side at home and (coach, Marco) Giampaolo is doing a great job here. We knew from the start it wouldn't be easy," Mancini told Mediaset.
"It's a good result for us after the winter break. We missed a chance for 2-0 and they had several chances to level because of mistakes we made."
With Inter, Fiorentina and Juventus all victorious, Napoli were under pressure but stayed in the hunt with a 2-1 win at home to Torino that moved them back up to third place at the expense of Juve.
Between Inter and fifth-placed Roma there are now just six points.
Lorenzo Insigne gave Maurizio Sarri's hosts a 16th minute lead when he collected Jose Callejon's delivery to send a delightful lob over the head of Torino 'keeper Daniele Padelli from outside the area.
At the other end, Pepe Reina produced a great one-handed save to keep out Fabio Quagliarella's pinpoint header, but the Spanish 'keeper was finally beaten by the former Juventus striker from the spot just after the half hour.
Torino were given the benefit of the doubt when Bruno Peres fell under a challenge from Faouzi Ghoulam, and Reina was unlucky after making solid contact with Quagliarella's spot-kick before it hit the back of the net.
Napoli, however, had the momentum in a dominant first half and Slovakian forward Marek Hamsik capped his 300th Serie A appearance with a superb angled strike four minutes from half time.
Torino came fighting back in a lively second half, when Sarri and Torino counterpart Giampietro Ventura were both sent from the touchline.
Inter weathered an early storm at the Castellani stadium, where veteran striker Massimo Maccarone, Riccardo Saponara and Piotr Zielinski were just off target for the hosts in a busy opening period that kept Inter 'keeper Samir Handanovic on his toes.
On the stroke of half-time Empoli were made to pay for those misses, Icardi pouncing at the near post to beat home 'keeper Lukasz Skorupski to Ivan Perisic's weighted delivery.
Remarkably, the Argentinian - who finished tied with veteran Verona striker Luca Toni on top of the league's scoring charts last season -- has only had 12 shots on target all season, with a return of eight goals.
Meanwhile, Juventus consigned their poor start to the campaign to distant memory with a commanding 3-0 win over Verona in Turin that left them fourth, still three points behind Inter and three ahead of Roma, who dropped points in a 3-3 draw away to Chievo.
Massimiliano Allegri's men have now won eight league games on the trot, and it came with relative ease after Argentina international Dybala put the hosts ahead after eight minutes.
A Leonardo Bonucci header on the stroke of half-time and Simone Zaza's late goal capped a comprehensive win for the Turin giants.
Allegri told Mediaset: "We're back among the leading pack: whoever makes the fewest mistakes will triumph."
He added: "We weren't great at the start of the game but we didn't concede anything to Verona.
"The lads did well, especially for a first game back after the holidays, but we're still not quick enough and we have to improve our technique."