The Serie A title race is becoming a one-horse race after Napoli lost 2-1 at home to Udinese on Sunday, leaving themselves six points behind leaders AC Milan.
Gokhan Inler and German Denis scored the goals to inflict the painful and possibly costly loss on Napoli, sending AC Milan pull away with five rounds remaining.
Napoli striker Edinson Cavani saw his weak penalty saved by Samir Handanovic with three minutes to go and his team trailing 2- 0.
Maurizio Domizzi got the marching order for conceding the spot kick when he hauled down Christian Lucarelli.
Napoli forward Giuseppe Mascara hit in a consolation goal in injury time, and then helplessly saw Udinese held on for the win.
Lazio remains three points behind third-placed Inter Milan in fourth after winning 4-1 at Catania. Udinese is a point behind Lazio.
Hernanes scored his ninth goal of the season for Lazio to open the scoring, just before halftime, but Ezequiel Schelotto equalized early in the second period.
Lazio's Mauro Zarate then took control of proceedings and set up Stefano Mauri and Sergio Floccari for goals, before he whipped in a free kick for Lazio's fourth in the 89th.
At the bottom of the table Cesena moved out of the Serie A relegation zone with a 1-0 win at home against Bari on Sunday.
Brescia slipped further behind in its efforts to escape the drop with a 3-0 defeat at Genoa. Rafinha scored the opener in the 59th, followed by an own goal from Gaetano Berardi 11 minutes later.
Luca Antonelli also scored in the 90th.
Brescia is two points behind Sampdoria, with Bari nine points adrift at the bottom of the table.
Also Sunday, Chievo Verona beat Bologna 2-0, Fiorentina drew 0- 0 with Juventus and Lecce tied 3-3 with Cagliari.