Juve head coach Antonio Conte's decision to withdraw misfiring strikers Sebastian Giovinco and Mirko Vucinic proved to be inspired as the latter's replacement pounced at the death to give the leaders a huge advantage with only 10 games remaining.
Napoli, meanwhile, were forced to watch their winless run extend to a seventh game in all competitions as Chievo sprung a surprise in Verona.
Chievo sealed victory in the first half thanks to goals from Boukary Drame and Cyril Thereau, while Edinson Cavani missed a penalty for Napoli.
Meanwhile, a week to forget for Inter Milan drew to a close in miserable fashion as Bologna condemned the Nerazzurri to a 1-0 defeat at the San Siro.
Coach Andrea Stramaccioni promised a spirited response to Thursday's 3-0 Europa League reverse at Tottenham, but a bumper crowd soon turned nasty as mid-table Bologna dominated from start to finish, with Alberto Gilardino's classy volley midway settling the tie.
Goals from Stevan Jovetic and Adam Ljajic took Fiorentina above both Lazio and Inter and into fourth thanks to a 2-0 win at the Stadio Olimpico.
Both sides were in the hunt for third place but Fiorentina had fresher ideas than the Biancocelesti and moved a point above their hosts and to within three of AC Milan.
An Amauri hat-trick saw Parma come from behind to snap an eight-game winless streak with a 4-1 victory over Torino.
Mario Santana opened the scoring in the 56th minute but that only served to inspire the Gialloblu, with Amauri levelling before Nicola Sansone fired Parma ahead with 10 minutes remaining.
With the floodgates open, Amauri found time and space to claim the match-ball with a well-taken double at the death.
At the other end of the table, Palermo are staring relegation in the face after letting a one-goal lead slip away against relegation rivals Siena, who closed to within two points of safety with a 2-1 victory.
When Anselmo opened the scoring just before half-time it looked like Palermo would leave their opponents behind and close in on 17th-place Genoa.
But goals from Innocent Emeghara and Alessandro Rosina left them staring at a return to the second tier after nine years at the top table.
Cristian Bucchi made a losing start as Pescara coach as a 2-1 defeat at Atalanta left the club rooted to the bottom of the table and five points from safety.
Gaetano D'Agostino gave Pescara the lead but German Denis levelled from the penalty spot within 10 minutes, before Denis' second finished Pescara off and moved Atalanta up to mid-table.
Elsewhere, Cagliari striker Victor Ibarbo scored a hat-trick to sink Sampdoria 3-1 with Maxi Lopez scoring a late penalty by way of a consolation.