The victory sees Vladimir Petković's side up into the third and final Champions League spot, leapfrogging AC Milan in their first win in five Serie A matches. Pescara, meanwhile, sink to their sixth defeat in their last seven, five points adrift of safety.
Lazio weren't overly impressive in the opening few minutes, though then again, neither were their opponents. Both teams struggled to make the ball stick in attack, with a long range snapshot from Pescara's Emmanuel Cascione deflecting into the arms of Federico Marchetti before a Sergio Floccari overhead kick went wide of the Ivan Pelizzoli's goal.
Eventually the hosts started to control the game, though continued to struggle to penetrate the disciplined Pescara ranks. The delfini sat deep and compactin defence, starting in an unfamiliar 3-5-2 shape. Lazio's Hernanes drilled wide from the edge of the area, before they finally took the lead from another ambitious effort.
Ştefan Radu scored his first Serie A goal after five years in Italy by smashing a first time shot into the top corner from the left side of the box just short of the half-hour, before Senad Lulić went one better, crashing a shot outside the area against the bar and back over the line for 2-0, leaving Pescara with a nigh-on impossible second half task.
They started the second half well, though they couldn't find a way through, and Lazio saw off the early barrage. Floccari should have killed the game when he was set through on goal by Hernanes just past the hour, though he hit his one-on-one straight at Pelizzoli from the left of the penalty area.
The biancocelesti were completely comfortable in the lead, and Marchetti had little to do in the entire second half.
Lazio (4-1-4-1): Federico Marchetti; Ştefan Radu, André Dias, Lorik Cana, Abdoulay Konko (Bruno Pereirinha 6); Cristian Ledesma; Senad Lulić, Hernanes, Álvaro González (Ogenyi Onazi 65), Antonio Candreva (Ederson 82); Sergio Floccari
Pescara (3-5-2): Ivan Pelizzoli; Uros Ćosić, Marco Capuano, Antonio Bocchetti; Luciano Zauri, Birkir Bjarnason, Emmanuel Cascione (Giuseppe Sculli 87), Giuseppe Rizzo, Antonio Balzano; Elvis Abbruscato (Gianluca Caprari 60), Mervan Celik (Milton Caraglio 71)
Goals: Radu 29 (L) Lulić 35 (L)