Milan striker Alexandre Pato came off the bench to score the winner against Chievo in a 2-1 victory.
The Brazilian latched onto a through ball by Gennaro Gattuso and shimmied his way through Chievo's defenders before unleashing a wonder strike that goalkeeper Stefano Sorrentino could do little about.
The valuable away win maintains Milan's five-point gap over second-placed Inter.
Lazio edged past bottom-placed Bari 1-0 at home thanks to a lone goal from Brazilian playmaker Hernanes, while Roma slumped to a third straight loss in outrageous fashion, losing 4-3 at Genoa despite leading 3-0 at the break.
Rodrigo Palacio and Alberto Paloschi scored braces for the hosts in the second half, providing yet another headache for under-fire Roma boss Claudio Ranieri.
Meanwhile, Udinese's upward momentum halted with a goal-less draw at home to lowly Brescia, Fiorentina and Sampdoria fought out a scoreless stalemate and Raffaele Palladino's 89th-minute equalizer salvaged a 2-2 draw for Parma against strugglers Cesena.