Milan's lacklustre season looks set to last the duration as they suffered defeat to Atalanta at the San Siro.
Carlo Ancelotti's men, who sat fifth at kick-off, suffered their third defeat in five games with a 2-1 loss to leave qualification for next term's UEFA Champions League seeming increasingly unlikely.
Atalanta struck twice in the space of 10 first half minutes as Sergio Floccari (32) opened the scoring and Antonio Langella (42) then added a second to stun Milan.
Ancelotti replaced the ineffective Giuseppe Favalli and Alberto Gilardino with Alberto Paloschi and Kakha Kaladze at the interval, but it was experienced defender Paolo Maldini who pulled back an 85th minute consolation.
But centre-back Alessandro Nesta was shown a straight red card for dissent late on to and Andrea Pirlo missed a penalty at the death to leave Ancelotti's future with last season's European champions also appearing increasingly uncertain.
Milan drop to sixth as Udinese stunned fourth-placed Fiorentina with a 3-1 win at the Stadio Friuli.
Gokan Inler had put the home side in front on 13 minutes, but Italian veteran Christian Vieri then restored parity just after the hour mark with a well-taken header.
However, things did not stay level for long as Antonio Di Natale (72) fired Udinese back in front following a swift counter-attack and Fabio Quagliarella (77) then tapped in a third after his initial effort had been blocked by Fiorentina goalkeeper Sebastien Frey.
Reggina's relegation worries continue as they suffered a 1-0 away defeat to Genoa.
Marco Borriello hit the back of the net in the 59th minute and Reggina were not capable of finding an equaliser.
Torino stole a march in the battle to avoid the drop as they defeated fellow strugglers Catania 2-1 at the Angelo Massimino.
Things started in explosive style as Gionatha Spinesi put Catania in front in the third minute.
Torino, though, shocked their hosts one minute later as Aimo Diana netted an equaliser.
Substitute David Di Michele then completed the turn around in the second half as he struck on 62 minutes to move Torino further away from danger.
Sampdoria boosted their plans for a place in Europe next season with a 2-0 away win against Empoli.
Paolo Sammarco opened the scoring on seven minutes before Lino Marzoratti put past his own goalkeeper to continue Sampdoria's plans for a place in the Uefa Cup.
Struggling Siena are looking nervously over their shoulders after a stalemate with Livorno at the Armando Picchi.
The point, though, does see Siena move level with fourth from bottom Cagliari.
In Sunday's evening kick-off Napoli left it late to secure a 1-0 win over Palermo at the Stadio San Paolo.
Marek Hamsik struck deep into stoppage time to secure the three points for the home side.
Juventus' meeting with Parma at the Stadio Olimpico was postponed as a mark of respect following the death of a visiting supporter at a motorway service station.