For much of the match, Mbappe was quite possibly the best player on a field he shared with some of the game's brightest lights over the last half decade or so: Vincent Kompany, Olivier Giroud, Romelu Lukaku, Antoine Griezmann, Kevin De Bruyne, Paul Pogba, Eden Hazard.
Samuel Umtiti's 51st-minute header in the semifinal sent the French into the final, where they will be seeking their second win since 1998.
Conversely Belgium were noticeably failing to emulate their first half form in the attacking third.
For all its possession, Belgium - the top scorers in this competition - were unable to break a robust French defense and will rue not capitalizing on its dominant first-half display.
Kompany, an injury-prone 32-year-old who may well have played his last World Cup in Russian Federation, believes that, despite the loss, the class of 2018 has done his nation a favor.
"The difference sadly is a set play in a very close and tight game", said Spaniard Martinez.
France booked their place in the semi-final with a comfortable 2-0 win over Uruguay, while Belgium's route here saw them defeat five-time winners Brazil in the quarters.More news: 4 kids,1 adult killed in Townsend, Del. crash
Henry, World Cup victor in 1998 with Les Bleus, is assistant coach to Roberto Martinez, manager of Belgium, beaten 1-0 in the semifinals this morning. I have not yet experienced that a striker plays so far from goal.
Didier Deschamps' France side failed to fire in their group matches but burst into life in the 4-3 demolition of Argentina as Mbappe overshadowed Lionel Messi and confirmed his arrival as a new superstar of the game.
Here are all the talking points from the 27th day of this summer's World Cup.
Tuesday's clash in St Petersburg has all the makings of a classic, with fans and viewers likely to be treated to the sight of two wonderfully attacking teams going toe-to-toe. His first touch was after 10 seconds and, after receiving the ball on the right wing, he sped past Jan Vertonghen and then Mousa Dembele in a thrilling run.
France and Belgium will meet Tuesday in St. Petersburg, after both teams booked their spots among the most talented in the 2018 staging of the soccer World Cup.
"I'm very proud of them, I'm very proud of their mentality as well because I know it's not just that you are playing at a high level that you are going to score goals but with our state of mind we can climb mountains and that's what we've done so far", said the French manager Deschamps. Marouane Fellaini was also slow to react when Umtiti scored with a near-post header.
"It is true it is a little peculiar to see him with the Belgium team", said Lloris.
Upon replay looked as if the Belgians had been withheld a legitimate free-kick opportunity as Giroud collected the front of Hazard's knees.