Alberto Paloschi's goal 61 minutes into an uneventful match inflicted second-placed Lazio's first loss since early November and they remained on 43 points, five behind the champions. Chievo moved up a place to 11th on 28 points.
Striker Paloschi tapped home his seventh goal in 10 appearances this season after Bojan Jokic's shot crashed against the bar and fell at the striker's feet, dealing a huge blow to Lazio's title hopes.
Juventus take on struggling Genoa in Turin in Saturday's late game (1945 GMT) with Antonio Conte's side looking to extend their lead at the top of Serie A to eight points.
