Milan slipped to their third consecutive Serie A defeat at home to Roma, while Fiorentina stunned Atalanta.
Francesco Totti set Roma on their way to a 2-1 victory over Milan with a brilliant volley in the seventh minute.
Milan came back strongly and twice hit the woodwork before Christian Brocchi drew them level with a ferocious, swerving shot from outside the area (56).
Roma were not finished though and restored their advantage when Totti headed home seven minutes from time.
Filippo Inzaghi thought he had rescued a draw for the Rossoneri in injury time but his effort was ruled out for offside.
Fiorentina left it late to beat Atalanta 3-1 and move closer to a position of safety in Serie A.
Atalanta took the lead through Giulio Migliaccio after 20 minutes but Adrian Mutu equalised just three minutes later.
The game appeared to be drifting towards a draw though, until two goals in the last two minutes from Giampaolo Pazzini secured victory for Fiorentina.
After starting the season with a 15-point penalty Fiorentina are now just one point away from climbing out of the relegation zone.
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