(Recasts after Roma loss)
Roma's hopes of qualifying for the Champions League suffered a setback as a five-match unbeaten sequence against Milan ended in a 2-1 defeat at the San Siro.
Goals by Marco van Ginkel and Mattia Destro, on loan from Roma, put Milan 2-0 up before Francesco Totti's late penalty set up a frantic finale but the hosts held on.
Roma remain in second place, 16 points behind champions Juventus who were earlier held 1-1 by relegation battlers Cagliari who equalised late on through Luca Rossettini.
Lazio can overtake Roma tomorrow with victory over Inter while fourth-placed Napoli, who are at troubled Parma, would close to within a point with a win.
Roma began strongly with captain Daniele De Rossi lashing a shot over the bar before Kostas Manolos headed against the upright with De Rossi poking the rebound wide.
Milan took the lead against the flow five minutes before halftime when Keisuke Honda broke clear and squared the perfect ball for Van Ginkel to steer a shot into the net.
Worse was to follow for Roma on the hour mark when Honda's inviting cross was met by Destro with a towering header to make it 2-0 to the Rossoneri.
Roma received a lifeline from a dubious penalty when Juan Iturbe went down under challenge from Nigel De Jong in the 72nd minute and Totti's weak effort found the net.
Despite intense pressure in the final minutes mid-table Milan held on.
Juventus clearly had their mind on Wednesday's Champions League semi-final second leg at Real Madrid, where they will defend a 2-1 lead, as they took on Cagliari with 10 changes from their midweek heroics in Turin.
With a fourth consecutive Serie A title already in the bag after last week's 1-0 win over Sampdoria, Juve were on course for a routine victory when Paul Pogba's deflected strike put them ahead on the stroke of halftime.
Rossettini equalised five minutes from time though to keep Cagliari's survival hopes alive.
With three games left Cagliari are in 18th place in the 20-team division with 28 points, five behind Atalanta who face Palermo tomorrow.