Peru reached their first Copa America final since 1975 by beating two-time defending champions Chile 3-0 in the second semi-final.
Edison Flores, Yoshimar Yotun and Paolo Guerrero all found the back of the net to put an end to Chile's dream of a third consecutive title, a feat only achieved once by Argentina in the 1940s.
Peru will now face hosts Brazil in the championship match in Rio de Janeiro on Sunday.
Flores opened the scoring in the 21st minute before Yotun fired into an empty net following a cross from Andre Carrillo to double the advantage in the 38th.
Guerrero slotted in a third in stoppage time to consolidate the lead.
Chile had a chance to claw one back in the final seconds, but Eduardo Vargas saw his penalty kick saved by Pedro Gallese.
Chile coach: We thought we were already through
Chile head coach Reinaldo Rueda, taking charge of Chile at a Copa America finals for the first time, blamed their defeat on complacency after an otherwise impressive run to the semi-finals.
"We entered the match already thinking about the final and that's how we allowed Peru to surprise us," he said. "We didn't show the attitude and aggressiveness from the previous matches.
"We faced a rival who managed to decide the game very soon, after just 20 minutes. We were not focused at the start of the game. It could have been due to a lot of factors, but it was something irregular and that we don't see often, because Chile did not show that strong attitude that we saw in other games and Peru profited from that.
"I think the second goal, who came from some of our own naivety, finished the game. Then (in the second half), Chile tried, and we reacted, but we had in front of us a team that had the psychological advantage of leading and who plays good football, and with a great goalkeeper who had a great night.
"He kept us from reducing the difference in the score."
When's the final?
Brazil will take on Peru in the Copa America final on July 7 at 9pm in Rio de Janeiro, with the hosts bidding to lift the trophy for the first time since 2007 - a short break compared to Peru's last triumph though, which came in 1975.
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