Frosinone fumbled a 2-0 lead against Sassuolo and are therefore mathematically relegated with three rounds to spare.
The Neroverdi had climbed into the top half of the table with last week’s win over Fiorentina, but missed suspended Federico Peluso and injured Magnani. Frosinone were still without Federico Viviani and Bartosz Salamon, knowing full well a defeat here would mean mathematic relegation to Serie B.
Frosinone took the shock lead after just eight minutes, as Paolo Sammarco hit it low and true first time from just outside the area, squirming into the far top corner.
Stefano Sensi had penalty appeals waved away, as he went down between two defenders when trying to get on the end of a Domenico Berardi roll across the six-yard box.
Berardi thought he’d equalised soon after, but the precise angled drive on the counter beat everyone only to bounce off the inside of the far post and back out again.
Andrea Pinamonti sprung the offside trap and was only denied by a desperate rush off his line by Andrea Consigli to fingertip it wide. However, on the resulting corner, Luca Paganini managed a glancing header into the far bottom corner from five yards to double Frosinone’s lead.
The hosts made a double change for the restart and Jeremie Boga drilled just wide from distance, although the conditions were increasingly difficult in torrential rain.
Sassuolo got back into it, as although Marco Sportiello made a great reaction save, the resulting corner found Gian Marco Ferrari to redirect the Rogerio effort from close range.
The momentum was suddenly the other way and Sassuolo equalised, as Pol Lirola rolled the ball across from the right and Jeremie Boga tapped in at the far post.
Frosinone needed to win in order to stave off relegation and thought they’d done it with a delightful Federico Dionisi lob, but he was flagged offside.
Sassuolo 2-2 Frosinone
Sammarco 8 (F), Paganini 35 (F), Ferrari 66 (S), Boga 77 (S)
Sassuolo: Consigli; Demiral, Lemos (Boga 46), Ferrari; Lirola, Sensi (Locatelli 80), Magnanelli, Bourabia, Rogerio; Berardi, Matri (Babacar 46)
Frosinone: Sportiello, Goldaniga, Ariaudo, Brighenti, Paganini, Cassata (Chibsah 70), Sammarco, Valzania, Beghetto, Ciano (D Ciofani 70), Pinamonti (Dionisi 82)