Mario Balotelli scored twice on his AC Milan debut to earn his new side a 2-1 victory over Udinese, but the nature of his winning goal arrived in typically controversial fashion.
All eyes were on the mercurial Italy striker following his £19million return to Italy and it took him only 24 minutes to open his account in Rossonero colours, even if the goal could have arrived much sooner.
Udinese made the most of the hysteria to spring a surprise at the San Siro in the second half, Gianpiero Pinzi souring the party atmosphere with a goal on the counter-attack.
Balotelli's head appeared to drop as Milan drifted towards a draw but he snatched up the ball with glee when Stephan El Shaarawy won a dubious penalty from Thomas Heurtaux.
The former Inter Milan striker did not miss from the spot and Udinese were left protesting the perceived injustice as Milan celebrated reaching fourth place.
Juventus went three points clear at the top of Serie A thanks to a 2-1 victory over mid-table Chievo at the Stadio Marc'Antonio Bentegodi.
An early strike by Alessandro Matri was followed by a second just before the break from Stephan Lichtsteiner, putting the visitors in control before Cyril Thereau reduced the arrears early in the second half.
Thereau had a chance to level the scores shortly after, but in truth it was a victory the league leaders deserved with Antonio Conte's side missing chances to extend their lead late on.
Siena climbed off the bottom of the Serie A table with a shock 3-1 victory over Inter Milan, who have now failed to win on the road since November.
Home debutant Innocent Emeghara, recently signed from Lorient, stunned the Nerazzurri with his first Siena goal only for Antonio Cassano to equalise inside 60 seconds.
It was a false dawn for Inter, though, as an Alessio Sestu goal ensured Giuseppe Iachini's men led their illustrious guests going into the break.
The second half might have been a different story for Inter had Cristian Chivu not seen red for a professional foul, with Alessandro Rosina converting the resulting penalty to settle the tie.
A last-gasp goal from debutant Marco Rigoni settled a frantic 3-2 victory over Lazio that lifted Genoa out of the Serie A relegation zone.
It was a well-deserved first win for new head coach Davide Ballardini, whose side built a two-goal lead inside 21 minutes thanks to goals from Marco Borriello and Andrea Bertolacci.
But the hosts would have to fight to the very end for the three points as Sergio Floccari and Stefano Mauri dragged Lazio back into the game, only for deadline-day signing Rigoni to fire Genoa up to 17th place with a bullet late header.
Palermo's rash of January transfer window signings were unable to change their fortunes at the foot of the Serie A table as they lost 2-1 at home to fellow strugglers Atalanta.
Palermo signed a total of 10 players in January, with Diego Fabbrini and Alejandro Faurlin the last to arrive on deadline day.
They both made their debuts but ended in a losing cause as second-half goals from Carlos Carmona and German Denis put Atalanta in control before Nelson's late consolation for the hosts.
Fiorentina got back to winning ways with a comfortable 2-0 victory over Parma at the Stadio Artemio Franchi.
Vincenzo Montella's men were chasing a first win in five games to restore their bid for a Champions League place and veteran striker Luca Toni put them on track with his ninth Serie A goal against Parma.
And the visitors, who are sliding down the league table, were condemned to a second straight defeat when Stevan Jovetic scored five minutes into the second half.
Pescara dropped into the Serie A relegation zone after losing 3-2 at home to Bologna in an eventful contest featuring three penalties in the space of 16 first-half minutes.
The home side twice took the lead from the spot through Vladimir Weiss and Gaetano D'Agostino, with Alessandro Diamanti initially equalising with a penalty for the visitors.
And Diamanti then set up a second equaliser for Alberto Gilardino before Panagiotis Kone scored what proved to be the winner midway through the second half.
The win lifted Bologna up to 14th, five points clear of the drop zone into which Pescara slipped due to Genoa's 3-2 win over Lazio.
On Saturday, Marek Hamsik took centre stage as Napoli moved level with Juventus at the top of Serie A with a 2-0 victory over Catania.
Hamsik grabbed a 31st-minute opener, turning in Camilo Zuniga's wayward shot, before his low cross set-up a Paolo Cannavaro tap-in just before half-time.
Catania were vastly improved after the break, and had a Gonzalo Bergessio header ruled out for a foul, but the hosts held on to draw level with Juve ahead of the champions' trip to Chievo on Sunday lunchtime.
Torino stretched their unbeaten run in Serie A to seven matches on Saturday but did little to set pulses racing in a goalless contest with Sampdoria at Stadio Olimpico.
The hosts impressed in a 2-2 draw at Inter Milan last time out but little of that fight was on display on Saturday, as they were cancelled out by a Samp side also on a high following last week's 6-0 win over Pescara.
The result does little for either side's bid to haul themselves out of mid-table obscurity.
On Friday, Cagliari romped to a convincing 4-2 victory in their grudge Serie A encounter with Roma at the Stadio Olimpico, and coach Zdenek Zeman was sacked the next day.
Francesco Totti got the Giallorossi back on level terms 10 minutes before half-time when he cancelled out Radja Nainggolan's early opener, but it was one-way traffic after the interval as a comical Mauro Goicoechea own goal and further strikes from Marco Sau and Francesco Pisano secured an emphatic away win before substitute Marquinho's late consolation.
The result was particularly sweet for the Rossoblu after the Eternal City club were awarded a 3-0 win without a ball being kicked in anger during September's ill-fated reverse fixture.