Brazil beat Mexico and Portugal ousted France, both by 2-0 scorelines, on Wednesday to set up a mouthwatering under-20 World Cup final.
France dominated for much of the game in Medellin against the Portuguese, but failed to find a way past a rock-solid defense that has yet to allow a goal in the tournament.
And they paid the price with two goals from set-pieces, Danilo heading in from a corner after just nine minutes and Nelson Oliveira slotting home a penalty five minutes from half-time.
"Congratulations to Portugal in reaching the final. but we really handed it to them," said France coach Francis Smerecki.
"We saw two different kinds of football in this game and it was the defensive one that came out on top.
"Their defense is so strong and there is no rule in football which says that you can't play with nine at the back. We lacked a bit of talent and spark and made too many technical mistakes."
Brazil were on top throughout against the Mexicans, but like France found it tough to find the net.
The breakthrough came in the last six minutes with a double from Henrique which made him joint top-scorer in the tournament on five goals alongside Spain's Alvaro Vazquez.
"Portugal are always a tough proposition and it will be tough for us just as it was against Spain and Mexico," said Brazil coach Ney Franco.
Saturday's final will take place in Bogota with Brazil going for a fifth title and first since 2003 at this level and Portugal a third after 1989 and 1995.