The Granata made the perfect start as they were awarded a penalty within five minutes when Nicolas Nkoulou's volley was handled by Ciro Immobile in the area.
Andrea Belotti, who had missed his last penalty against Parma stepped up and confidently sent Thomas Strakosha the wrong way to give Toro the lead.
Ciro Immobile had two excellent chances to make amends for the concession of that penalty but on both occasions blazed high over the bar.
However, just three minutes into the second half, the former Toro striker finally grabbed his goal, with a clever finish across Salvatore Sirigu.
With less than twenty minutes remaining and Toro hoping to cling on to a valuable point, Marco Parolo's deflected effort from just outside the area gave Sirigu no chance and was enough to give Lazio all three points.