There were plenty of talking points from a dramatic night in Milan, which saw two players sent off and play suspended for two minutes by referee Gianluca Rocchi shortly after half-time.
The Tuscan official used new league rules to halt play while a stadium announcement was issued to a section of Roma fans, who were heard directing abuse at several Milan players.
Sulley Muntari had earlier fallen foul of Rocchi at the end of the first half, earning a bizarre red card for dissent, but despite having an extra man Roma failed to find a winner before losing captain Francesco Totti for his elbow on former team-mate Philippe Mexes.
The Rossoneri must now wait until the final day of the campaign to match or better fourth-placed Fiorentina's result, while Roma's only hope of a foray into Europe rests on success in the Coppa Italia final, where they face Lazio.
Fiorentina kept themselves within touching distance of Milan by beating Palermo 1-0 and condemning the Sicilians to relegation, Luca Toni scoring the only goal at the Stadio Artemio Franchi.
And playing alongside the Rosanero in Serie B will be Siena, whose fate was sealed before the Tuscans had kicked a ball in anger.
Giuseppe Iachini's men started the day six points shy of 17th-placed Genoa and knew their destiny was out of their own hands when Inter Milan visited the Stadio Luigi Ferraris.
The Rossoblu duly registered a goalless draw against Inter to secure their own future and render Siena's later game at Napoli a dead rubber.
Walter Mazzarri's Azzurri, who guaranteed themselves a second-placed finish with victory over Bologna in midweek, were given a stern examination as the Bianconeri took a shock lead through debutant Fabrizio Grillo.
But the San Paolo faithful demanded one last push and Edinson Cavani duly headed home his 35th goal of the season in the second half before Marek Hamsik settled a 2-1 win deep into stoppage time.
Udinese and Lazio are desperate to secure Europa League football by booking fifth place and the Romans kept in touch with their northern rivals by beating Sampdoria 2-0.
After a brace from Antonio Di Natale saw Udinese overturn Giuseppe De Luca's early goal to beat Atalanta 2-1 at the Stadio Friuli, Lazio managed to edge out 10-man Samp in the capital city.
Sergio Floccari opened the scoring at the Stadio Olimpico and Antonio Candreva rubber-stamped the points with a penalty after Samp substitute Renan was dismissed for dissent.
Elsewhere, Bologna claimed all three points from the Emilia Derby as Saphir Taider and Davide Moscardelli scored the goals to beat Parma 2-0, while Torino claimed a 1-1 draw with Chievo with Alessio Cerci cancelling out Cyril Thereau's opener.