Inter Milan held on to beat 10-man Fiorentina 4-2 and hand boss Stefano Pioli his first win since taking charge.
Four days after throwing away a two-goal lead to lose to Hapoel Be'er Sheva and exit the Europa League, Inter were almost pegged back in Serie A despite leading 3-0 after 19 minutes.
Marcelo Brozovic, Antonio Candreva and Mauro Icardi all scored early for the hosts but Nikola Kalinic pulled one back and, after Gonzalo's controversial dismissal in first-half stoppage time, Josip Ilicic got another.
But Icardi struck in stoppage time to inflict a first defeat in seven league games on Fiorentina.
Gregoire Defrel's stunning equaliser snapped Sassuolo's losing streak and handed Napoli's Scudetto hopes another blow.
Defrel's late volley cancelled out Lorenzo Insigne's opener as Napoli were held to a 1-1 draw -- their third stalemate in a row at the Stadio San Paolo in all competitions.
Insigne cut in from the left before letting fly with a deflected strike that beat Andrea Consigli and gave the hosts a deserved 42nd-minute lead.
But Sassuolo improved after the break and ended a run of four straight league defeats when Marcello Gazzola's fine cross from the right was brilliantly dispatched on the volley by Defrel from near the penalty spot.