Juventus eased the pressure on coach Ciro Ferrara with a 3-0 win over Napoli in Round 5 of the Coppa Italia, while AC Milan left it late against Novara and Catania surprised Genoa.
The Bianconeri had lost four of their last five games in all competitions going into the game with Ferrara's position reported to be under threat if they suffered another defeat to in-form Napoli.
Diego broke the deadlock after 24 minutes with a controversial strike as he carried on to score despite Napoli's Jesus Datolo lying injured on the floor.
Alessandro Del Piero put the game beyond Napoli, who suffer their first defeat under coach Walter Mazzarri, with two second half goals - his second from the penalty spot - to set up a mouthwatering quarter-final meeting with rivals Inter later this month.
Mathieu Flamini's late goal earned AC Milan a hard-fought 2-1 win over minnows Novara to send the Rossoneri into the last eight.
Milan coach Leonardo made a host of changes to his side for the game against the third tier outfit and one of those, Filippo Inzaghi, gave the hosts the lead after just 12 minutes.
However, Novara, who arrived at the San Siro sitting top of Girone A in Lega Pro Prima Divisione and with an unbeaten record in all competitions so far this season, refused to be overawed and they drew level a minute after the restart with Pablo Gonzalez finding the net.
With the game heading towards extra time, Milan grabbed the winner nine minutes from time when Flamini scored with a powerful curling shot into the top corner from the edge of the box.
Catania dumped Genoa out of the competition after a surprise 2-1 win at the Stadio Luigi Ferraris to book a quarter-final clash with Roma.
Sinisa Mihajlovic's men raced into a shock 2-0 lead in the opening 10 minutes with a brace from Gianvito Plasmati.
Marco Rossi gave Genoa hope with a thunderous strike on 57 minutes, but things took a turn for the worse for the home side just 60 seconds later with two players seeing red.
Sokratis Papastathopoulos was dismissed for a second bookable offence and Rossi joined him for protesting at the decision.
The remaining three ties in the last 16 take place on Thursday.
Fifth Round Results
Wednesday 16 December 2009
Inter 1-0 Livorno
Tuesday 12 January 2010
Roma 3-1 Triestina
Wednesday 13 January 2010
Milan 2-1 Novara
Genoa 1-2 Catania
Juventus 3-0 Napoli
Fifth Round Fixtures
Thursday 14 January 2010
Fiorentina v Chievo (1500)
Udinese v Lumezzane (1730)
Lazio v Palermo (2000)
20/21/27/28 January 2010
Milan v Udinese/Lumezzane
Fiorentina/Chievo v Lazio/Palermo
Roma v Catania
Inter v Juventus
* All kick-off times listed are UK time (+1 for Italy/CET). Times, dates and fixtures are subject to change.
Coppa Italia Fifth Round Reviews
[16 Dec 2009] - [12 Jan 2010] - [13 Jan 2010] - [14 Jan 2010]
Source: Sky Sports