Contrasting wins for Napoli and Inter Milan kept them hard on the heels of leaders Juventus in Serie A on Sunday but Fiorentina lost ground after being held at home by improving Sampdoria.
Napoli had a thumping 5-1 win over bottom club Pescara but Inter scraped an unconvincing 1-0 victory at home to Palermo.
Two goals each by Gokhan Inler and Edinson Cavani, one from the penalty spot, helped Walter Mazzarri's Napoli side stay two points behind Juve, who defeated local rivals Torino 3-0 on Saturday.
Inter are four points behind Juve on 31 after ending a run of three games without a win thanks to an own goal by Palermo's Santiago Garcia.
Stefan Savic scored both Fiorentina goals in a 2-2 draw which earned a point after Nenad Krsticic and a Gonzalo Rodriguez own goal had seen Sampdoria equalise then take the lead. Savic's goals were his first in Serie A.
"Honestly I'm happy with our position, it's a shame that it's not the end of the season now, or at least within a couple of games," Fiorentina coach Vincenzo Montella told reporters.
"We came up against a Sampdoria side that caused us problems, and while we weren't brilliant we had enough opportunities to win.
Fiorentina are in fourth place, level on 29 points with Lazio and two behind Inter Milan as Samp moved up to 12th on 17.
Lazio are six points off the pace in fourth spot after beating Parma 2-1 thanks to a 25th-minute effort from defender Giuseppe Biava and Miroslav Klose's ninth league goal of the season.
Ishak Belfodil pulled one back for Parma in the 66th minute, converting the rebound after his penalty was saved.
Napoli 5 (Inler 9, 78, Hamsik 15, Cavani 58-pen, 63) Pescara 1 (Birkir 18)
Siena 1 (Neto 25) Roma 3 (Destro 63, 90+1, Perrotta 86)
Udinese 4 (Pereyra 33, Angella 39, Danilo 48, Pasquale 66) Cagliari 1 (Dessena 80)
Genoa 2 (Said Said 40, Jankovic 56) Chievo 4 (Paloschi 14, 22,
45+1, Stoian 89)
Bologna 2 (Diamanti 16, Gabbiadini 70) Atalanta 1 (German 50)
Inter Milan 1 (Garcia 74-og)
Lazio 2 (Biava 25, Klose 34) Parma 1 (Belfodil 66)
Fiorentina 2 (Savic 21, 75) Sampdoria 2 (Krsticic 48, Rodriguez 72-og)