A late Sergio Pellissier strike extended Chievo's winning streak to three games and gave them a first Serie A victory over Roma at the Bentegodi.
Roma saw their four game victory roll get lost in the Verona fog, as the Chievo substitute netted the game's only goal with just two minutes to play. The Flying Donkeys are the first side to stop Roma from scoring in Serie A this season.
Michael Bradley started against his former club. Erik Lamela was back from injury, but had to settle for a place on the bench alongside Daniele De Rossi. Pablo Daniel Osvaldo was eligible to start as his upcoming ban only applies to the Coppa Italia.
Roma pressed in the opening period, but found the Chievo rearguard as solid as the pitch, which was hard and frozen in parts.
Halfway through the first period, Francesco Totti volleyed just over from an acute angle inside the box. Fernandez Castro picked up a booking which will rule him out of next week's game with Milan. Dario Dainelli met Cyril Thereau's free-kick on 25 minutes, but saw his header deflect wide.
Roma continued to get forward before the break. Totti's auspicious chip went over, Alessandro Florenzi volleyed wide and Bradley saw a shot charged down by Chievo's resolute defence.
A bout of half-time fog led to the floodlights being turned on for the second half. Mauro Goicoechea clawed Luca Rigoni's header off the line after Thereau's cross picked him out perfectly.
Just before the hour, Osvaldo rose above two markers to head wide of the post. Shortly after, the forward was sent clear, but a poor final touch allowed Sorrentino to run out and smother the ball.
As the fog worsened, Marquinhos clashed with Goicoechea and needed medical attention. Florenzi too was in the wars and Goicoechea was called into action to save a tame Thereau shot. Ivan Piris found space in the area, but Sorrentino got down well to stop the ball creeping into the corner.
Federico Balzaretti went down under a heavy challenge in the box and looked for a penalty. Play went on and two substitutes combined for the unlikely victory. Marco Rigoni picked out Pellissier with a long ball, the frontman got by Goicocehea and slotted the ball home.
Chievo: Sorrentino, Sardo, Dainelli, Andreolli, Drame, Guana, L.Rigoni, Cofie, Hetemaj, (Jokic 76) Thereau, (M.Rigoni 85) Paloschi (Pellissier 67)
Roma: Goicoechea, Piris, Marquinhos, Castan, Balzaretti, Bradley, (De Rossi 68) Tachtsidis, Florenzi, Pjanic, (Lamela 64) Osvaldo, Totti (Destro 72)
Goal: Pellissier 88 (C)