Marek Hamsik surpassed Diego Maradona's long-standing goalscoring record for Napoli as the Azzurri pulled clear at the top of the Serie A table.
The Slovakia midfielder, who scored the first of his 116 goals for Napoli in August 2007, fired what proved to be the winner in a topsy-turvy 3-2 triumph over Europa League-chasing Sampdoria.
Gaston Ramirez had put Samp ahead at the San Paolo, with Fabio Quagliarella restoring their lead from the penalty spot after Allan had equalised.
Lorenzo Insigne levelled from a Dries Mertens pass after the half-hour, with Hamsik soon tucking away a second assist from the Belgian to relegate Maradona to second place in the scoring charts.
Napoli left-back Mario Rui was dismissed for two bookable offences, but the hosts survived to secure a four-point lead before Juventus host Roma later on Saturday.
Inter Milan would have hoped to keep in touch with Napoli by winning at Sassuolo, but instead they went down 1-0 thanks to a Diego Falcinelli strike in the 34th minute.
Mauro Icardi had an opportunity to grab a point, but his penalty after the break was saved by Andrea Consigli and Inter remained in third place.
Lazio and Ciro Immobile called time on their respective lean spells by hammering Crotone 4-0.
After a first half of toil, Jordan Lukaku opened the scoring by tucking away Immobile's pass.
Italy striker Immobile then found his 16th league goal of the season, ending a four-game drought. Substitute Senad Lulic provided the assist that the former Torino hotshot headed home.
Relegation-threatened Crotone were put to bed when Bosnian midfielder Lulic put away Felipe Anderson's pass at the death, with the provider adding gloss to the scoreline in stoppage time.
Antonin Barak scored twice as Udinese recorded a fourth straight win with a 4-0 home thumping of Hellas Verona.
The Czech midfielder kicked off the rout and added the third goal after Silvan Widmer got in on the act, leaving the in-form Kevin Lasagna to propel Udinese further clear late on.
Mirco Antenucci rescued a point for lowly SPAL as his penalty forced a 2-2 draw at home to Torino.
Iago Falque notched twice - his first goal arrived after just 17 seconds - but Federico Viviani slashed the deficit before former Leeds striker Antenucci made Lorenzo De Silvestri pay for his foul.
Elsewhere, Benevento were moments away from just a second point this term, which was taken away from them when Gianluca Lapadula won and converted a stoppage-time spot-kick to make it 1-0.