Atalanta scored twice in the final 21 minutes to come from 1-0 down and shock Lazio with a 2-1 victory in the Serie A clash at Atleti Azzurri D'Italia.
The home side were unbeaten in their four league games in front of their own fans so far this season and they took the initiative in the opening stages, Alejandro Gomez testing Federico Marchetti from the edge of the box before seeing another effort blocked inside the first six minutes.
In contrast to the hosts' strong home form Lazio had lost three of their four away matches so far this season, but they took the lead with 19 minutes on the clock thanks to a fine strike from Lucas Biglia, the captain sending a free kick over the wall and past Marco Sportiello from 25 yards.
Lazio piled on the pressure after going in front as Ogenyi Onazi tested Sportiello from distance, but shortly after half time Mauricio Pinilla fired the visitors a warning shot when he drilled wide.
Pinilla came close with two further attempts as the hosts increased the pressure, but Stefano Pioli's side did not heed the signs and they handed Atalanta an equaliser when Dusan Basta turned into his own net on 69 minutes.
With four minutes to go the turnaround was completed when Alejandro Gomez met Marco D'Alessandro's centre to shock Lazio and secure a fourth win in five home games for the hosts.