A 1-0 home defeat to Palermo relegated Cagliari to Italy's Serie B on Sunday as Genoa and Torino scored valuable wins to maintain their hopes of qualifying for the Europa League.
With Juventus crowned champions a fortnight ago and the fight for Champions League places ongoing between Lazio and Roma, Sunday's early fixtures held mixed fortunes for Serie A's also-rans.
A 2-1 home defeat to Juventus on Saturday compounded Inter Milan's chances of qualifying for the Europa League and Roberto Mancini's men remain eighth, now three points behind sixth-placed Fiorentina in the third and last Europa qualifying spot.
Across the city, nerves are jangling just as much with the distinct possibility of neither Milan side making it into Europe next season.
A hat-trick from Sassuolo striker Domenico Berardi in a 3-2 home win over AC Milan ended the slim hopes the seven-time European champions' had of Europa qualification.
But Milan were not the only side holding their heads in disappointment, Cagliari started the day knowing anything less than a win would prove fatal and the Sardinians were a goal down after just nine minutes when
Franco Vazquez struck for the Sicilians, who held on to their 1-0 lead to move up to 10th place.
Cagliari have now joined Cesena and Parma in Serie B a day after Frosinone, a club based 50 km south of Rome, joined Carpi in grabbing one of three promotion places to Italy's top flight.
Among the day's biggest winners were Genoa and Torino, both of whom remain in contention for a Europa League place although the latter's chances appear slim.
Hosts Atalanta took an 18th minute lead from the spot against Genoa thanks to Pinilla, but the Bergamo-based side were stunned by four successive goals from the visitors including a brace from Iago Falque.
Genoa's 4-1 win moved them up to fifth place, one point ahead of Fiorentina, and pushed city rivals Sampdoria down to seventh and out of the Europa League reckoning.
A brace by Maxi Lopez handed Torino a precious 2-0 home win over Chievo that left the Granate in ninth place but now only four behind Fiorentina.
If Fiorentina slip up against Parma on Monday, Sampdoria, Inter and Torino -- with only three points separating the sides -- will see their European chances given a boost.
Roma host Udinese in Sunday's late game looking to restore their one-point lead on Lazio as the city rivals battle for the second automatic Champions League qualifying spot.
Napoli, in fourth at four points behind Roma, host Cesena on Monday looking for the win that would cement their Europa League place as well as maintain their hopes of catching Roma over the closing two games.