Lazio failed to capitalise on Serie A's top four all dropping points as they were beaten 3-1 at home by Torino with Ciro Immobile's sending off just before the break a major turning point.
Simone Inzaghi's men went into the clash eight points off the top of the table with two games in hand and looked excellent at times in the first half, but a moment of madness from Immobile gave Torino the encouragement they needed.
Shortly after being denied a penalty despite his cross striking Iago Falque's hand, Immobile latched on to a pass and smashed his effort against the post, before appearing to headbutt Nicolas Burdisso to earn a red card once referee Piero Giacomelli had consulted video evidence.
Alex Berenguer put the visitors ahead soon after the interval, cutting on to his right foot on the left side of the area and finding the bottom-far corner.
Tomas Rincon doubled the lead in the 64th minute, producing a sublime finish into the top-left corner after a fine solo run.
The hosts pulled one back shortly after thanks to a lovely run and finish from Luis Alberto, but it did not take Torino long to restore the two-goal lead, as Simone Edera curled in from 20 yards to wrap up an impressive triumph for Sinisa Mihajlovic's men - their first league win at Lazio since November 1993.
