GENOA - Sampdoria sent Inter to their first defeat of the 2009/10 season, Giampaolo Pazzini doing the damage midway through the second half as the Blucerchiati extended their unbeaten home run to twelve matches.
It was going to take something special to decide this highly tactical affair at the Stadio Luigi Ferraris, and the Italian striker finished off a clinical move in the 72nd minute to put his team on top of the Serie A table ahead of Sunday's matches.
José Mourinho named Mario Balotelli in the starting lineup for the first time this season, with Vieira slotting in at right midfield alongside Zanetti and Cambiasso as Inter changed formation after Wednesday's home win over Napoli.
His Sampdoria counterpart Luigi Del Neri made four changes to the team that lost 2-0 to Fiorentina in midweek, bringing in Ziegler, Lucchini, Poli and Bellucci.
Balotelli made a lively start and our first shot on target came from his right foot in the 22nd minute. Castellazzi saved it and the Sampdoria keeper was kept busy a minute later when Cambiasso shot low on goal after combining with Milito.
Il Principe, back at his old stadium for the first time since his summer switch from Genoa, carved out a chance for himself on the half hour but shot straight at Castellazzi after ghosting past three opponents.
Sampdoria's best chance of the first half fell to Ziegler in stoppage time. The Swiss midfielder fired a right-footed shot on target but Julio Cesar said no with a punched save.
Both coaches stuck with their starting XIs after the restart and the match remained tactical with both sides playing compact football - Balotelli's shot deflected off Gastadello and Pazzini's shot wide via Maicon the only chances of the opening period.
A tight game called for changes and Mourinho brought off Balotelli and Vieira, replacing them with Stankovic and Chivu who offered the Nerazzurri more thrust in midfield.
Spotting his team under pressure, Del Neri replied with Tissone for Poli and Zauri for Bellucci. Samp reorganised quickly and took the lead from a swift move that caught the Inter defence by surprise. Palombo's low pass into the box found Mannini, who set up Pazzini to slot past Julio Cesar.
Quaresma for Cambiasso was Mourinho's reply and the Portuguese winger almost celebrated his 26th birthday by salvaging a point in the closing stages. He pounced on a loose ball after a corner was cleared and saw his shot diverted in off Lucio, only for the Brazilian to be flagged offside.
Lucio could have equalised in time added on but Castellazzi made the save of the match to keep out his fierce curling free kick.
Sampdoria 1-0 Inter (HT: 0-0)
Scorer: Pazzini 72.
Sampdoria: 1 Castellazzi; 3 Ziegler, 6 Lucchini, 28 Gastaldello; 7 Mannini (19 Franceschini 81), 23 Stankevicius, 17 Palombo, 16 Poli (12 Tissone 65); 11 Bellucci (8 Zauri 69), 10 Pazzini, 99 Cassano.
Subs not used: 21 Guardalben, 9 Pozzi, 13 Rossi, 22 Cacciatore.
Coach: Luigi Del Neri.
Inter: 12 Julio Cesar; 13 Maicon, 6 Lucio, 25 Samuel, 39 Santon; 14 Vieira (5 Stankovic 61), 4 Zanetti, 19 Cambiasso (7 Quaresma 73), 4 Zanetti; 45 Balotelli (26 Chivu 62), 22 Milito, 9 Eto'o.
Subs not used: 1 Toldo, 2 Cordoba, 18 Suazo, 30 Mancini.
Coach: José Mourinho.
Referee: Nicola Rizzoli (Bologna).
Booked: Palombo 25, Lucchini 35, Cassano 39, Maicon 57, Gastaldello 78.