Carrasco opened the scoring in the 37th minute. Lukaku then doubled Belgium's lead in the 40th minute with a right-footed shot into the near corner.
It looked like an easy ride for the Red Devils before the break. But France showed fighting spirit and fought back after the interval, with Benzema scoring after the hour mark and Mbappe equalising in the 82nd minute.
In the 87th minute, Lukaku thought he'd score a double but his goal was disallowed for offside.
And shortly after that, Theo Hernández netted France's winner.
Former Chelsea players Eden Hazard and Thibaut Courtois played for Belgium, with Eden getting involved in both Belgium's goals and Tibo pulling off a few nice saves.
Michy Batshuayi, on loan at Besiktas from Chelsea, was brought on in the added time but he didn't have time to have an impact on the game.
France will face Spain in the Nations League final on October 10.
