Kamil Glik's first-half strike was all that separated the two teams in Turin although Lazio came close to an equaliser with a couple of missed chances.
The outcome allowed Torino to continue their improved form, which has seen them lose just two of their last nine league games, and leapfrog Lazio in the Serie A table.
Toro have climbed to seventh place while Lazio, who have failed to emerge triumphant in their last six league games, have fallen to 12th position.
Lazio dominated possession in the early stages of the game but struggled to break Torino's well-placed defence and it was the hosts that went in front in the 19th minute.
Lazio failed to clear Danilo D'Ambrosio's cross in the heart of the area and Glik took advantage and fired a right-footed shot past Biancoceleste goalkeeper Federico Marchetti.
The visitors almost equalised two minutes later when Senad Lulic's header from Abdoulay Konko's cross went just over the bar.
Midway through the first half, Marchetti kept out Alessio Cerci's shot from just outside the area.
Before half-time, Lucas Biglia warmed the hands of Daniele Padelli with a stinging drive from 30 yards that the Torino goalkeeper did well to clear.
Lazio picked up where they left off after the re-start and in the 48th minute, Hernanes' effort went just over the bar.
Shortly after, Antonio Candreva's right-footed volley was kept out by Padelli as Lazio pressed forward more aggressively.
In the 67th minute, substitute Sergio Floccari's attempt from 20 yards went inches wide of the far post.
Padelli was forced to fully stretch in the 80th minute to clear Candreva's bullet strike from 30 yards.
Lazio wasted a good chance to equalise with eight minutes remaining when Honorato Ederson's cross found substitute Keita in the box and his right-footed shot went over the bar.
Torino defended deeply and held on for three valuable points.