The hosts were made to pay for a lack of clinical finishing when Antonio Di Natale scored a controversial winner, from what appeared to be an offside position, a minute after the break.

The defeat saw Juve surrender their lead to Roma at the top of the standings, while Udinese's first league win of the season propelled them up to mid-table.

Roma maintained their unbeaten start with a 2-0 victory at 10-man Reggina.

Brazilian defender Juan broke the deadlock five minutes after the break with a clever backheel.

Matters went from bad to worse for the hosts when Carlos Valdez was sent off a minute later, before Francesco Totti compounded their misery with a second goal six minutes from time.

Inter Milan moved up to second as they warmed up for their Champions League trip to Fenerbahce with a 2-0 victory over Catania at the San Siro.

Elsewhere, Napoli beat Sampdoria 2-0 and Atalanta drew 2-2 against Fiorentina. Palermo versus Torino finished 1-1, as did Genoa v Livorno and Parma v Cagliari.