Liverpool star Luis Suarez scored both goals in the second half at La Plata as the Uruguayans, who put out hosts Argentina in the quarters, kept on course for what would be a record 15th win in the world`s oldest international football tournament.
"It was a very tough game in the first half and we lacked a little clarity though we kept trying to make chances," said Suarez, who went level in the scoring stakes with Argentina`s Sergio Aguero on three goals.
Referring to a more cagey affair against Argentina in the previous round he told broadcaster TyC Sports: "This was a game where we had to come out and attack and fortunately that`s what we did."
Experienced coach Oscar Tabarez, who led the Charruas to the World Cup semifinals last summer, said experience was the key to success.
"We had to draw on all our experience. The group has known each other a long time.
"We are very very happy to be in the final - but Sunday is still a long way away. We will need to maintain our organisation and discipline."
After a bright start by Peru, with Luis Advincula looking lively in midfield, Uruguay increasingly found their feet and began to boss the encounter.
But the Peruvians held them at bay, without ever looking as if they would pull another rabbit out of the hat, having knocked fancied Colombia out at the quarterfinal stage.
After the break, veteran forward Diego Forlan began to turn the screw for the Uruguayans and it was the Atletico Madrid man who finally found a way through seven minutes after the restart.
The former Manchester United misfit fired in a majestic left-footed shot which keeper Raul Fernandez was only able to parry and Suarez reacted in a flash to bury the rebound from point blank range.
Five minutes later the Celeste put the contest to bed, Suarez beating the offside trap and sidestepping the keeper before sliding home into the empty net.
With Forlan increasingly bossing the game, the Uruguayans, whose last title came in 1995, could have extended their advantage.
But Peru would not lie down and Paolo Guerrero hit a speculative effort which Fernando Muslera in the Uruguayan goal did well to clutch at the second attempt.
However, the Peruvians, whose second and last title to date came in 1975, had given themselves too much to do after the second goal and their mission was impossible after Bolivian referee Raul Orosco sent off Juan Vargas midway through the second period for a foul on Sebastian Coates.
"We stood up well to them - but this is football and now we have to switch focus to the World Cup qualifiers," said Guerrero.
Paraguay meet Venezuela in the other semifinal on Wednesday.