Serie A wrap: Novara stun Lazio
Lazio's Antonio Candreva scored an own goal on 35 minutes but was relieved as Giuseppe Mascara equalised two minutes later.
Frenchman Mobido Diakite scored the winner in the 79th minute, however, condemning Lazio to their fifth loss in eight games.
Lazio remain third on the Serie A table but have had their advantage cut to one point, with Napoli breathing down their necks in fourth place, while Novara are in 19th position - still seven points from safety with only four games remaining.
Slovak Marek Hamsik and in-demand Uruguayan Edinson Cavani scored on either side of half time as Napoli outclassed relegation-threatened Lecce 2-1 in Lecce.
Napoli's win ensured Udinese slipped to fifth following their 3-1 loss at home to Inter Milan.
Wesley Sneijder netted a brace and Ricardo Alvarez added a third before half-time after Danilo had opened Udinese's account in the sixth minute.
Fiorentina moved further away from the drop zone with an upset 2-1 win over Roma at the Stadio Olimpico.
Francesco Totti cancelled out Stevan Jovetic's opening goal before the visitors secured the three points courtesy of Andrea Lazzari in injury time.
Pablo Osvaldo was sent off for Roma.
Siena hosted Bologna in a 1-1 draw and Parma came from a goal down to defeat Palermo 2-1.