Daniele De Rossi's penalty 10 minutes from time helped AS Roma beat Genoa 3-2 on Saturday to move within one point of Serie A leaders Inter.
Champions Inter can re-establish their four-point advantage at Atalanta on Sunday but will be without injured top scorer Zlatan Ibrahimovic.
Genoa forward Marco Borriello needlessly brought down Rodrigo Taddei and Rossi blasted the ball home to spare second-placed Roma's blushes after throwing away a two-goal lead. AC Milan also cut the gap on fourth-placed Fiorentina to a point after Filippo Inzaghi and Kaka returned from injury to score in a 3-1 home win over struggling Cagliari.
Kaka burst forward and unleashed a superb shot to give Milan an early lead before Inzaghi glanced home Andrea Pirlo's 31st-minute corner thanks to more charitable defending.
The Sardinians were given hope when Zeljko Kalac, in good form since replacing Dida as Milan's number one, allowed Daniele Conti's free kick to roll in under his body before Inzaghi netted his second in the 69th minute.
Carlo Ancelotti's side, who lost 2-1 at home to Atalanta last weekend, go above Udinese into fifth with Cagliari remaining third from bottom. Fiorentina host lowly Reggina on Sunday.