Siena suffered an embarrassing 2-0 home defeat to third-tier outfit Novara in Round 4 of the Coppa Italia while Chievo beat Frosinone by the same scoreline.
A Pablo Andres Gonzalez brace saw Novara, who have already surprised Modena and Parma in the cup this season, record a memorable giant-killing of Serie A's bottom side Siena.
The Tuscan club, who prop up the top flight with just six points from 13 games, came into the game with Alberto Malesani at the helm following the sacking of Marco Baroni earlier this week, but Siena's second managerial change of the season failed to arrest their poor form.
Goals either side of the break from Gonzalez secured the victory for Novara, who are in a good run of form and pushing for promotion at the top of Lega Pro Prima Divisione.
The win secures a dream Round 5 date with AC Milan for the Piedmont-based club.
In the day's other fourth round encounter, strikes from Younness Hanine, on the half-hour, and Simone Bentivoglio, in stoppage time, saw 10-man Chievo post a routine 2-0 win over Serie B side Frosinone.
The Flying Donkeys booked a last 16 meeting with Fiorentina despite playing with a man less for the final 25 minutes after having Marco Malago sent off.
The fourth round continues on Thursday with three further fixtures, and will be completed next week with the remaining three matches.
Fourth Round Results
Wednesday 25 November 2009
Chievo 2-0 Frosinone
Siena 0-2 Novara
Fourth Round Fixtures
Thursday 26 November 2009
Atalanta v Lumezzane (1400)
Napoli v Cittadella (1930)
Palermo v Reggina (1930)
Tuesday 1 December 2009
Triestina v Sassuolo (1900)
Sampdoria v Livorno (1930)
Wednesday 2 December 2009
Catania v Empoli (1400)
Fifth Round Draw
10, 15 December 2009, 13 January 2010
Fiorentina v Chievo
Lazio v Palermo/Reggina
Juventus v Napoli/Cittadella
Inter v Sampdoria/Livorno
Milan v Novara
Udinese v Atalanta/Lumezzane
Roma v Triestina/Sassuolo
Genoa v Catania/Empoli
* All kick-off times listed are UK time (+1 for Italy/CET). Times, dates and fixtures are subject to change.
Coppa Italia Fourth Round Reviews
[25 Nov 2009] - [26 Nov 2009] - [1 Dec 2009] - [2 Dec 2009]
Source: Sky Sports