Juventus beat bitter rival Inter Milan 2-1 in an entertaining match at San Siro to provisionally extend its Serie A lead to 12 points on Saturday.
It took Juventus less than three minutes to take the lead with a stunning strike from Fabio Quagliarella.
Rodrigo Palacio leveled in the 55th but Juventus was back in front five minutes later when Alessandro Matri fired in from close range.
Inter's Esteban Cambiasso was sent off for a brutal tackle on Sebastian Giovinco as the final whistle sounded.
Napoli could cut Juve's lead back to nine when it faced Torino late Saturday.
AC Milan also plays Chievo Verona later, knowing it can take a huge step towards securing a Champions League berth after Fiorentina and Roma lost.
Lazio came from behind to beat Catania 2-1.
At the other end of the table Genoa drew 2-2 with Siena in a relegation battle.
Juventus was keen for revenge after Inter ended its 49-match unbeaten streak in November. And it got off to the perfect start when Quagliarella curled a shot into the top right corner from 25 yards.
Juventus almost doubled its lead shortly afterwards but Leonardo Bonucci headed over from close range.
Inter could have leveled in the 12th minute with a long-range effort from Antonio Cassano which Gianluigi Buffon did well to tip round his right post at full stretch.
Buffon did even better moments later with a fantastic reaction save to keep out Rodrigo Palacio's point-blank header.
It was Palacio who leveled 10 minutes after the interval, collecting Cassano's pass and forcing his way into the area before slotting past Buffon.
Juventus' riposte was quick when Quagliarella just managed to keep Arturo Vidal's ball from going over the byline and crossed for Matri to tap home at the near post.
Inter was seven points off third and leapfrogged by Lazio.
Lazio's Lorik Cana hit the bar in a first half full of missed chances. It looked like Lazio would pay for its woeful finishing when Catania took the lead five minutes after the break, after Stefan Radu's clearance ricocheted in off Mariano Izco.
However, the match turned on its head 11 minutes from time.
Nicola Legrottaglie slid in to prevent Radu's ball from reaching Libor Kozak but succeeded only in prodding past his own goalkeeper to gift Lazio the equaliser.
Lazio was in front two minutes later when Giuseppe Bellusci gave away an unnecessary penalty, shoving over Ederson on the far side of the area. Antonio Candreva fired the penalty into the bottom right corner.
Lazio was a point behind fourth-placed Fiorentina which lost 2-1 at Cagliari in front of an empty stadium as Is Arenas was again closed to fans because of safety issues.
Mauricio Pinilla scored both goals for Cagliari in the first half, including a penalty after Juan Cuadrado tripped Marco Sau.
Cuadrado grabbed one back for Fiorentina 16 minutes from time.
Roma remained level on points with Inter after it suffered a shock 2-0 defeat at relegation-threatened Palermo.
Josip Ilicic and Fabrizio Miccoli scored for Palermo which also hit the woodwork twice.
Palermo moved off the bottom spot and was just three points from safety after Genoa's draw with Siena.
Pescara was six points from safety after it lost 3-0 at Parma.
Elsewhere, Antonio Di Natale had a penalty saved as Udinese drew 0-0 at home to Bologna. There was also a goalless draw between Atalanta and Sampdoria.