AC Milan's mini-revival came to an abrupt end as Fiorentina inflicted a fourth home defeat of the Serie A season on Massimiliano Allegri's hapless side, beating them 3-1.
• Blog: Mad Max in a Milan mess
Following a dismal start to the season, things were finally starting to look rosier for the Rossoneri after a thumping victory over Chievo saw them climb into the top half of the table last week.
But Alexandre Pato failed to peg back Vincenzo Montella's Viola before the break, missing a penalty after Alberto Aquilani managed to open his goalscoring account for the Tuscans.
Borja Valero then beat Christian Abbiati to give Fiorentina a two-goal lead but substitute Giampaolo Pazzini hit back on the hour mark to give Milan hope. However, there was ultimately no way back for a toothless Milan side when Mounir El Hamdaoui made the visitors' points safe at the death with a long-range screamer.
It was no better for the other half of Milan as Inter fell to a 3-2 defeat away in Atalanta.
Giacomo Bonaventura gave Atalanta an early lead which lasted until 11 minutes into the second half when Fredy Guarin equalised. German Denis restored Atalanta's lead instantly before adding a third from the penalty spot in the 67th minute.
Rodrigo Palacio brought Inter back into the game in the 84th minute and Atalanta were reduced to 10 men when Facundo Parra was dismissed in stoppage time, but the Bergamese side held on to the points to move up to sixth in the table.
Lazio inflicted a third straight 'Derby della Capitale' defeat on Roma , 3-2, to hold on to bragging rights in the Eternal City, with Stefano Mauri's goal proving key as both sides had a man sent off.
Erik Lamela temporarily lifted the Giallorossi above their fiercest rivals in the league table, scoring his seventh goal in six games with a confident header at the Stadio Olimpico. But Vladimir Petkovic's Lazio seized control on a waterlogged pitch, Antonio Candreva and Miroslav Klose notching to turn the tables on Roma before half-time.
Daniele De Rossi conspired to get himself sent off in first-half stoppage time and Mauri clinched all three points with a close-range finish after the restart.
Napoli kept up the hunt for the Scudetto with a 4-2 win at Genoa, who have now lost five in a row, four under the guidance of Luigi Del Neri.
Walter Mazzarri's side came from behind twice before reserving their best for last with two late goals earning them all three points at the Stadio Luigi Ferraris. Ciro Immobile put Genoa in front midway through the first half, but former Genoa defender Giandomenico Mesto levelled early in the second half.
Andrea Bertolacci restored Genoa's lead almost immediately before Edinson Cavani brought Napoli level again with just over 10 minutes to go. Napoli threw everything forward and were rewarded when Marek Hamsik put them in front for the first time in the last minute, and Insigne then completed the win with the last kick of the game.
Gabriele Angella's 91st-minute strike earned a point for Udinese two minutes after Alberto Paloschi's spot-kick looked to have won the 2-2 draw for their hosts Chievo.
Udinese's equaliser came when they only had 10 men after Danilo was sent off, having received a second yellow for the foul on Cyril Thereau which led to the penalty being awarded.
Marco Andreolli had put the hosts in front after 38 minutes, although Angella was on hand to equalise four minutes later.
Palermo have a new hero after 18-year-old striker Paulo Dybala scored his first two goals in Serie A to down Sampdoria 2-0 at the Stadio Renzo Barbera.
Dybala stepped into the void left by an injury to Fabrizio Miccoli and scored twice in the second half, going close to completing his hat-trick too as he earned the Sicilians all three points.
Danilo D'Ambrosio's goal brought Torino's six-game winless run to an end with a 1-0 win to see off lowly Bologna. The defender headed home Mario Santana's cross from close range on 65 minutes and while Bologna came close to an equaliser the hosts held on for an overdue three points.
Parma are still unbeaten at home since March but a 0-0 draw with Siena did little to boost their chances of securing European football.
The Crociati dominated proceedings but could not find a way past a resilient Gianluca Pegolo, whose impressive goalkeeping earned Siena a valuable point in their quest for survival.
Information from the Press Association was used in this report