Milan gave their great rivals Internazionale the chance to open up a 20-point lead at the top of Serie A as they held Roma to a 1-1 draw on Saturday night.
The Giallorossi are trailing in Inter's wake this season and could only inch one point closer despite taking the lead at Stadio Olimpico - with Roberto Mancini's champions elect taking on Parma on Sunday.
French defender Philippe Mexes struck after just three minutes for the capital club as Roma took an early lead.
However, Milan drew level when Italian international striker Alberto Gilardino scored just after the hour mark.
The draw sees the Rossoneri move to within three points of Palermo and a UEFA Champions League place.
Siena dented Reggina's survival hopes with a 1-0 victory in a game that saw both clubs reduced to ten men.
Reggina suffered an early blow when Alessandro Lucarelli was dismissed for a professional foul after 22 minutes.
Siena took advantage of their numerical superiority when Valerio Bertotto netted on 46 minutes.
However, they guaranteed themselves some late nerves when Daniele Corvia followed Lucarelli in receiving a red card for violent conduct.
Victory moves Siena up to 13th in Serie A, with Reggina remaining just one point above the relegation zone.