Atalanta had the chance to climb the standings, but instead were pegged back by bottom club Chievo and an extraordinary Riccardo Meggiorini strike.
Cagliari survived a late piece of Federico Chiesa brilliance to beat Fiorentina 2-1 on Friday and pile more pressure on Viola boss Stefano Pioli.
Aurelio Andreazzoli’s return to the Empoli bench coincided with a precious victory that practically dooms Frosinone and keeps the Tuscans out of the bottom three.
Juventus have lost their Serie A unbeaten record with a shock 2-0 defeat to Genoa, with late goals from Goran Pandev and their former player Stefano Sturaro.
Lazio flattened Parma in no uncertain terms with four goals in the first half alone, including a Luis Alberto brace, to climb the standings.
Inter emerged with an extraordinary 3-2 victory over rivals Milan to leapfrog them into third place in a dramatic, chaotic, passionate Derby della Madonnina.
Napoli escaped two scares to beat Udinese 4-2, as they fumbled a 2-0 lead and saw David Ospina stretchered off after a head injury.
Sampdoria dominated Sassuolo with a crushing 5-3 away victory, providing quality as well as quantity, including Fabio Quagliarella’s 21st goal of the season.
The Claudio Ranieri effect has already worn off, as Roma were beaten 2-1 by a SPAL side who hadn’t won at home for six months.
Sinisa Mihajlovic took revenge on his old club, as Bologna earned a shock 3-2 victory away to Torino in a game with disallowed goals and two red cards, ruining their European ambitions.