Argentina's San Lorenzo were pelted with objects by rival fans and needed protection from police at halftime of their 1-0 loss to Bolivar in their Libertadores Cup semi-final second-leg but managed to advance to the final for the first time.
The Argentine side had held a comfortable 5-0 advantage from last week's first-leg and sat back to defend in two lines of four, 3,600 metres up on Bolivia's Andean plateau.
Substitute Gerardo Yecerotte scored the only goal for Bolivar in the second minute of added time on a poor Hernando Siles pitch.
San Lorenzo will meet Nacional of Paraguay, also first time finalists after beating Uruguay's Defensor Sporting 2-1 on aggregate on Tuesday, over two legs for the South American club title and a place in the Club World Cup in December.
"We made a great effort, we've got one more step to fulfil our dream of winning the Cup," playmaker Leandro Romagnoli said. "We weren't able to play (Bolivar) as equals because of the matter of the altitude and that annoys us, but we achieved our objective," he told Fox Sports.
The match was preceded by a minute's silence in memory of Argentine FA president Julio Grondona who died earlier in the day aged 82.