Sassuolo join Roma, Fiorentina and Inter in the Europa League group stage after a draw with Red Star.
Domenico Berardi put the Emilian side ahead in the first half to all-but secure progression, Aleksandar Katai’s equaliser restored pride for the Serbians.
The Neroverdi went into the second leg of their play-off with a 3-0 lead, having dominated the first leg.
Nonetheless, Eusebio Di Francesco fielded a strong side, making just two changes from the first leg, with Alessandro Matri making his debut.
Sassuolo join Roma, Fiorentina and Inter in the Europa League group stage after a draw with Red Star.
Domenico Berardi put the Emilian side ahead in the first half to all-but secure progression, Aleksandar Katai’s equaliser restored pride for the Serbians.
The Neroverdi went into the second leg of their play-off with a 3-0 lead, having dominated the first leg.
Nonetheless, Eusebio Di Francesco fielded a strong side, making just two changes from the first leg, with Alessandro Matri making his debut.
It was the former Juventus striker who provided the first threat, hitting the post with just under 15 minutes on the clock.
Matteo Politano forced a save from an Alfred Duncan cross, before the deadlock was broken on 28 minutes.
Having scored four goals in just three Europa League games, Domenico Berardi beat the offside trap to pick the ball up wide on the right.
The Italian Under-21 international produced some fancy footwork to cut in on his favoured left-foot, before surprising Damir Kahriman with a near-post shot.
That put Neroverdi 4-0 ahead on aggregate, leaving Red Star needing five second half goals without reply prevent Di Francesco’s side advancing to the Group Stage.
Matri was having a debut to forget. Having kneed over from only a few yards in the first half, he missed two chances in one when he hit straight at Kahriman before a fresh air shot with the goal gaping.
On 54 minutes, Katai put his side back in the match if not the tie, beating Andrea Consigli with a fine low strike.
Much like the first leg, Sassuolo were dominating and substitute Diego Falcinelli drilled wide after Matri dummied a Berardi cutback.
Both sides knew the tie was realistically over, with neither truly coming close to another goal in the remaining minutes.
The result sees Sassuolo advance to the Group Stage of the Europa League in their first-ever season of European competition.
Red Star 1-1 Sassuolo
Berardi 28 (S) Katai 54 (RS)
Red Star: Kahriman; M. Cvetkovic (Babunski, 80), Le Tallec (Rendulic, 57), Phibel, Ristic; Donald, Poletanovic; Ruiz (Srnic, 85), Katai, Mouche
Sassuolo: Consigli; Lirola, Cannavaro, Acerbi, Peluso; Biondini, Magnanelli, Duncan; Berardi (Letschert, 72), Matri (Trotta, 83), Politano (Falcinelli, 62)