|Reigning champions AC Milan (pictured) are still chasing smaller club Udinese despite thrashing Catania 4-0 [EPA]
Unsung Udinese moved top in the Italian league with a 2-1 win over Siena on Sunday after previous leaders Juventus had their match at Napoli postponed due to flash floods.
Dusan Basta put Udinese in front less than a minute in at the Friuli stadium and Antonio Di Natale scored his league-leading eighth of the season in the 64th before Francesco Bolzoni pulled one back for Siena in the 76th.
Based in Udine near the Slovenian border, Udinese's best finish in Serie A was third in 1998 when former Germany international Oliver Bierhoff scored 27 goals.
Lazio are level with Udinese after they edged Parma 1-0 with an 85th-minute goal from Giuseppe Sculli, but Udinese hold the edge on goal difference.
Defending champions AC Milan also jumped in front of Juventus with a 4-0 rout of Catania for their fifth consecutive win.
Zlatan Ibrahimovic, Robinho and Gianluca Zambrotta scored for Milan, who also got an own-goal from Catania midfielder Francesco Lodi.
Udinese and Lazio have 21 points each, Milan have 20 and Juventus are fourth with 19.
Milan were playing their first match since Antonio Cassano underwent minor heart surgery on Friday, and fans at the San Siro dedicated a series of banners to the forward.
Genoa flood tragedy
Inter Milan's match at Genoa was also postponed due to flooding, and a minute's silence was held before each match in honour of the six people killed in the coastal city on Friday.
The league did not immediately set new dates for the Juve-Napoli and Genoa-Inter games.
Inter remained just barely above the relegation zone, ahead of Lecce only on goal difference.
Ten-man Lecce won 1-0 at last-place Cesena with a 56th-minute goal from Colombian forward Juan Cuadradoto, ruining the debut of new Cesena manager Daniele Arrigoni.
Also, Chievo Verona beat Fiorentina 1-0 with a 66th-minute goal from Luca Rigoni to heap more pressure on Fiorentina manager Sinisa Mihajlovic; and Atalanta edged Cagliari 1-0 with an 81st-minute goal from German Denis - the Argentine's seventh of the season.