Samuel Umtiti says the France defence has been inspired to "go to war" by the efforts of their midfield and attacking team-mates.
Didier Deschamps' side defeated world champions Germany 2-0 in Marseille on Thursday to reach the final of Euro 2016.
Les Bleus spent plenty of time out of possession and under pressure at Stade Velodrome, particularly in the first half, but international newcomer Umtiti claimed the hosts were ready for a struggle against Joachim Low's heavyweights.
"We expected not to have the ball," he was quoted as saying by L'Equipe.
"We were prepared for it. We knew that technically they are very strong. We had to be very good defensively. That's what we did and it paid off. When we see the efforts of the wingers and the midfield, we say we can go to war with them.
"For me, this is exceptional. To play and win against such a team, without conceding a goal, it's a great satisfaction."
Umtiti, expected to join Barcelona from Lyon after the tournament, only made his senior international debut in the quarter-final victory over Iceland as a replacement for the suspended Adil Rami but looked assured as France kept a clean sheet to book a showdown with Portugal on Sunday.
"I tried to be calm once again and play with my qualities, as I know [how] to do with my club," he said.
"We must raise our level in this kind of game... playing alongside these players, it's not complicated. It [helps you] adapt easily."
Asked if he was more comfortable pulling on the national team shirt for the second time on the big stage, he said: "Yes, it's true ... I felt better. [But] it is not easy for my second match to be a semi-final of the Euro."
Umtiti will now be expected to retain his place in the starting XI ahead of Rami, who had been available for the semi-final after serving his suspension but was not recalled, having struggled earlier in the tournament.
Pressed on whether or not he believes he will stay in the team for the decider, the Cameroon-born 22-year-old said: "I do not know at all.
"We never know. The coach will have to make choices and we will accept them.
"I do not let it go to my head. I live from day to day. I take what happens, because honestly, I did not expect it."