Innocent Emeghara scored twice as Siena beat Lazio 3-0 to derail the Rome club's Champions League qualification hopes.
The hosts started brightly and were ahead in the seventh minute when Emeghara found room at the back post to powerfully head home Matteo Rubin's cross.
Lazio looked vulnerable in defence throughout the contest and fell further behind midway through the first half, with an unmarked Alessandro Rosina tapping in from close range.
Despite improving slightly after the interval, Lazio were struggling to find an answer to the power of Emeghara and the forward doubled his personal tally with a smart finish following a defensive mistake to put the result beyond doubt just after the hour mark.
Lazio went close to snatching a consolation goal in the closing stages when substitute Ederson fired his long-range effort against the crossbar but Siena scrambled the ball to safety to secure a clean sheet and a comfortable victory.
