Lazio are heading towards an eighth straight win Serie A, having taken a 3-0 lead at the halfway stage of their clash with Empoli.
The visitors made a bright start to the game and Daniele Croce threatened in the second minute when he drove into the box and fired in a strike from a tight angle that was pushed behind by Etrit Berisha.
From the resulting corner they came close again as Daniele Rugani met the ball at the back post, but he could not direct his effort on target.
Just a minute later the home side were in front as Stefano Mauri met Luis Pedro Cavanda's delivery from the right and directed a header beyond Luigi Sepe.
Lazio doubled their lead in the 31st minute when Cavanda swung another precise cross into the box and Miroslav Klose was on hand to power in a firm header.
With a minute left to play in the first half Lazio scored their third goal of the match, as Antonio Candreva fired in a strike from range that left Sepe helpless as it found the corner of the net.
Mauri almost made it four for Lazio on the stroke of half time, but after latching onto Klose's flick and volleying into the corner, his effort was ruled out for offside.