The loss at their Armando Picchi stadium kept Livorno second from bottom.
It was Livorno's seventh reverse in eight games and while coach Davide Nicola tried to revive his troops with a post-match discussion on the pitch the hosts only had themselves to blame.
Both sides created a series of half-chances but Parma put the match beyond reach in the space of seven minutes at the death when Amauri hit a brace.
Amauri's first came largely thanks to Massimo Gobbi, whose angled drive came off Bardi's post and into the the path of the Italian striker Amauri who stroked the ball home.
Amauri had his second goal, and third in two games, when he stepped up to beat Bardi from the spot after Pedro Mendes was tripped by Emerson.
In the late game Bologna came closest to scoring in a stale first half at the Renato dell'Ara stadium, where Lazio were looking to claim their second successive win under new coach Edoardo Reja following the recent sacking of Vladimir Petkovic.
Bologna are hovering two points above the relegation zone.