Torino drew 0-0 at Lazio on Tuesday to assure their presence in Serie A next season but the stalemate condemned Benevento to relegation with a game to play.
The game was held over from 2 March due to a Covid-19 outbreak at the Turin club.
The precious point from the rescheduled match at the Stadio Olimpico looked an improbable outcome with Ciro Immobile's 84th-minute penalty and Manuel Lazzari's injury-time header both hitting the woodwork.
Torino, in 17th, moved to safety, four points clear of Benevento, their final day opposition this weekend.
Benevento drop back to Serie B after just one season along with already demoted Crotone and Parma.