Sassuolo secured a sixth-place finish and kept their chances to qualify for next season's Europa League alive with a season-closing 3-1 Serie A victory over 10-man Inter on Saturday.
Eusebio Di Francesco's side have never played European football before but will now be hoping for a Juventus victory over AC Milan in next weekend's Coppa Italia final, which would be enough for them to seal a continental berth.
Milan's defeat to Roma ultimately made Sassuolo's victory irrelevant in the race for sixth, but that result was not known when Matteo Politano's deflected strike put the home side in the box seat after six minutes at Citta del Tricolore.
Lorenzo Pellegrini doubled the advantage with another goal against the run of play before Rodrigo Palacio finally got Inter off the mark.
Politano popped up again to restore Sassuolo's lead before the interval and a questionable offside decision against Danilo D'Ambrosio early in the second half indicated it was not Inter's day.
Jeison Murillo's red card for a two bookings in a matter of seconds only strengthened that viewpoint, but Sassuolo will be grateful of the chance to embark on a historic European campaign.
Inter's fourth-place finish was already secure, but Roberto Mancini's side – which contained five changes - applied the initial pressure, Stevan Jovetic flagged offside before slotting beyond goalkeeper Andrea Consigli.
However, a lapse in concentration at the other end cost Inter possession in a dangerous area and Politano took full advantage, sending a deflected strike past Juan Pablo Carrizo in the Inter goal.
Politano was mobbed by his team-mates after sending the hosts in front, but Consigli was soon called into action to tip over after a cross bounced goalwards off Francesco Acerbi.
The Sassuolo defence came under pressure as Inter probed for a leveller in the torrential rain, yet the Nerazzurri were hit with another sucker punch when Pellegrini slid in to convert an Alfred Duncan ball across the six-yard box midway through the half – the goal awarded after brief confusion over a potential foul in the build-up.
The scoreline belied Inter's dominance of first-half possession and Consigli had to get down to his right to keep out a Jovetic header, before the Montenegro international saw an effort bounce just over after fortuitously avoiding an offside flag.
Inter's persistence eventually paid off after 31 minutes when Palacio received the ball from Marcelo Brozovic, who had dispossessed the dawdling Francesco Magnanelli, to curl a low strike around Consigli.
But Sassuolo's two-goal cushion was restored six minutes from the break thanks to Politano's powerful header from Marcello Gazzola's delivery.
Inter looked to have pulled another goal back within two minutes of the restart, when D'Ambrosio was incorrectly denied by a late flag following Geoffrey Kondogbia's ball into the box.
A clumsy foul by Murillo on Diego Falcinelli, coupled with his angry reaction, earned the Colombian his marching orders just short of the hour, and Mancini's decision to hand teenage Romanian goalkeeper Ionut Radu his debut in the closing stages suggested he felt there was no way back for his side.
And Sassuolo held on relatively comfortably to keep their end of the European qualification bargain – over to Juve.
