Second-placed Roma are eight points behind Juve with five matches to play including a meeting between the pair at the Stadio Olimpico.
Bottom side Pescara are down after one season in the top flight as the defeat left them 15 points adrift of 17th-placed Empoli, the team immediately above the drop zone, but with a worse head-to-head record.
Roma moved four points clear of third-placed Napoli in the race for Italy's second automatic slot in nesxt season's Champions League group stage.
The only sour note for Roma was that Edin Dzeko, Serie A's joint leading scorer with 25 goals, reacted angrily to being substituted in the second half and refused to shake coach Luciano Spalletti's hand.
Read the full article on eurosport.co.uk: Rampant Roma condemn Pescara to Serie B