BARCELONA - Inter were beaten 1-0 on the night but progress through to the 2009/10 UEFA Champions League final with a 3-2 aggregate victory over Barcelona.
The Nerazzurri survived an out-and-out siege in the Camp Nou after playing over an hour in ten men following the dismissal of Thiago Motta.
Gerard Piqué struck late on and Bojan had a goal ruled out after a hand ball by Tourè, but it was too little, too late for the defending European champions.
José Mourinho had named an unchanged team from last week's win in Milan but was forced into a late switch when Goran Pandev pulled up with a muscle strain. Cristian Chivu took the Macedonian's place and slotted into midfield with Arnautovic going on the bench.
Barcelona boss Josep Guardiola made two changes from his first-leg lineup, bringing in Gabriel Milito and Yaya Tourè for Maxwell and suspended captain Carles Puyol.
The hosts pinned back Inter from the outset, but the Nerazzurri managed to suffocate the Barça passing machine with Walter Samuel making some vital interceptions to deny Messi and co. a way through.
Barça's bid to reverse the 3-1 defeat from the first leg received a boost on 28 minutes when Thiago Motta - already on a yellow card - was harshly shown a straight red by De Bleeckere for shoving Busquets in the face.
But for all their efforts Barcelona failed to raise the tempo and even when they did get sight of goal there was Julio Cesar to get past and the Brazilian goalkeeper produced a magnificent tipped save from Messi's curling shot just past the half-hour mark.
Inter's ten heroes kept the Blaugrana at bay after the interval with Eto'o and Milito helping out in defence, Samuel and Cambiasso making Messi look ordinary, and Lucio fighting tooth and nail to protect Julio Cesar's goal.
Barcelona sub Bojan summed up his team's night on 82 minutes when he nodded wide Messi's cross with the goal gaping, but two minutes later Piqué provided a lifeline, receiving in the area from Xavi and turning Cordoba and Julio Cesar before tucking into an open net.
More nail-biting drama for Inter fans followed in the closing minutes as Julio Cesar made important saves from Xavi and Messi, and Bojan had a goal disallowed after a hand ball by Tourè.
Inter face Bayern Munich in the final at Madrid's Estadio Santiago Bernabeu on Saturday 22 May. The treble dream is alive and kicking.
Barcelona 1-0 Inter (HT: 0-0; AGG: 2-3)
Scorer: Piqué 84.
Barcelona: 1 Valdes; 2 Dani Alves, 3 Piqué, 18 G.Milito (19 Maxwell 46), 15 Keita; 6 Xavi, 24 Tourè; 16 Busquets (35 Jeffren 63); 10 Messi, 9 Ibrahimovic (11 Bojan 63), 10 Pedro.
Subs not used: 13 Pinto, 4 Marquez, 14 Henry, 34 Thiago Alcantara.
Coach: Josep Guardiola.
Inter: 12 Julio Cesar; 13 Maicon, 5 Lucio, 25 Samuel, 4 Zanetti; 19 Cambiasso, 8 Thiago Motta, 26 Chivu; 9 Eto'o (17 Mariga 86), 10 Sneijder (11 Muntari 77); 22 D.Milito (2 Cordoba 81).
Subs not used: 1 Toldo, 23 Materazzi, 45 Balotelli, 89 Arnautovic.
Coach: José Mourinho.
Referee: Frank De Bleeckere (Belgium).
Booked: Thiago Motta 10, Pedro 27, Julio Cesar 35, Chivu 43, Muntari 82, Lucio 82.
Sent off: Thiago Motta 28.