TURIN - Samuel Eto'o cancelled out Alessandro Del Piero's opener at the Stadio Olimpico in Turin but Claudio Marchisio scored a second-half winner as Inter fell to their first away defeat against Juventus since October 2005.
The 2-1 reverse at the Stadio Olimpico sees Inter's Serie A lead cut to four points with AC Milan making up points thanks to their home win over Sampdoria in Saturday's early game.
The first derby d'Italia of the season was a predictably tense affair and Saccani was constantly reaching into his pocket for yellows and reds, with José Mourinho sent off in the first half and Juventus reduced to ten men in the closing minutes after the dismissal of Felipe Melo.
Ciro Ferrara's side took the lead on 20 minutes. Diego swung in a free kick, Melo and Del Piero diverted it on target but the final touch appeared to be off the knee of Lucio, changing the trajectory and tricking Julio Cesar who got a hand to the ball but couldn't keep it out.
Drama ensued as Mourinho was sent off for applauding Saccani and mouthing 'bravo' at the referee for his decision to award the free kick which led to the goal.
Eto'o, who let Milito take the penalty which gave us victory over Fiorentina last weekend, said he was saving his goal for the derby d'Italia and the Cameroonian striker kept his promise as Inter produced a swift reply.
Buffon palmed away Samuel's header but Stankovic worked the ball back into the box and Eto'o popped up unmarked to head home his first away goal in Serie A after six in Milan.
Inter produced a double chance to edge in front after the interval but Grosso blocked Stankovic's effort before Buffon saved Eto'o's follow-up.
Juventus hit straight back and retook the lead through Marchisio, who leapt on to a loose ball and took it round Samuel before lifting over Julio Cesar after the Inter keeper had palmed away Sissoko's low shot.
Tempers flared in a nervous finale with incidents involving pairs of players from both teams, the most significant being a tit-for-tat between Melo and Balotelli which resulted in the sending-off of the Brazilian midfielder.
Juventus 2-1 Inter (HT: 1-1)
Scorers: Del Piero 20, Eto'o 26, Marchisio 58.
Juventus: 1 Buffon; 2 Caceres, 5 Cannavaro, 3 Chiellini, 6 Grosso; 22 Sissoko, 4 Melo, 8 Marchisio (18 Poulsen 81); 28 Diego (21 Grygera 90+1); 11 Amauri, 10 Del Piero (16 Camoranesi 71).
Subs not used: 13 Manninger, 17 Trezeguet, 20 Giovinco, 33 Legrottaglie.
Coach: Ciro Ferrara.
Inter: 12 Julio Cesar; 4 Zanetti, 6 Lucio, 25 Samuel (23 Materazzi 90), 26 Chivu; 8 Thiago Motta, 19 Cambiasso (30 Mancini 79), 11 Muntari (45 Balotelli 60); 5 Stankovic; 9 Eto'o, 22 Milito.
Subs not used: 1 Toldo, 2 Cordoba, 14 Vieira, 15 Krhin.
Coach: José Mourinho.
Referee: Massimiliano Saccani (Mantua).
Booked: Muntari 23, Melo 25, Samuel 28, Grosso 61, Amauri 80, Melo 87, Balotelli 87, Caceres 90+3.
Sent off: Mourinho 21, Melo 87.