Chilean side Cobreloa claimed a crucial 1-0 away win against Tacuary in the first leg of the Copa Sudamericana first round.
The away goal could prove crucial in the second leg in Calama on 7
Troncoso told Fox Sports: "It was a very complicated game, but fortunately we managed to make it.
"We are now a little bit relaxed ahead of the second leg, but we must be careful anyway. We must keep this attitude."
Midfielder Matias Melazzi was the first to hit the post in the 23rd minute, while a header by Fabricio Formiliano from a free-kick also hit the frame of the goal seven minutes before half-time.
A late equaliser from Miguel Caneo earned Quilmes a 1-1 draw against Argentine Clausura leader Newell's Old Boys while Boca Juniors accounted for Colon.