England came from behind to defeat eight man France 3-1 after extra time, and qualify for the European Under-19 Championship final for a second time. France opened the scoring early on through Magaye Gueye before Henri Lansbury drew England level eight minutes before the break.
England pushed for the winner after the break only to be denied by the brilliance of the French keeper Remi Pillot.
And Delfouneso struck his second in this first period of extra-time when he rounded the keeper and coolly slotted home.
Ryad Boudebouz and Abdel El Kaoutari were both then sent off in the closing stages.
England will face either Serbia or hosts Ukraine in the final on Sunday.