Inter Milan snapped a three-match winless run in the league with a 2-0 victory over struggling Udinese.
Romelu Lukaku netted the opener in the final quarter of the second half before adding a second from the penalty spot moments later to take his side three points off the leaders.
Lazio were back to winning ways with a 5-1 thumping of SPAL at the Stadio Olimpico.
Top scorer Ciro Immobile and Felipe Caicedo each netted a first-half double, with substitute Bobby Adekanye netting the fifth early in the second half.
SPAL's consolation came from Simone Missiroli, who netted after the 65th minute leaving his side in the bottom-half.
AC Milan failed to close into the top-six bracket following a 1-1 draw against Hellas Verona.
Verona were ahead through Davide Faraoni inside the opening 13 minutes, but Turkish international Hakan Calhanoglu restored parity on 29 minutes.
The visitors finished with a man down inside the 65th minute after Sofyan Amrabat received a straight red card.
Atalanta jumped back into fourth place despite playing to a 2-2 draw against relegation-threatened Genoa.
Atalanta raced into an early two-goal lead through Raphael Toloi and Josip Ilicic, before a penalty from Domenico Criscito later in the half and Antonio Sanabria's effort sealed a draw for the visitors.