Pierre Sage's team will face Strasbourg or Nice in the final on May 22. Lens have never lifted the cup in the club's 120-year history, finishing runners-up three times.

Florian Thauvin tucked away an early penalty at an expectant Stade Bollaert-Delelis after he was brought down in the area by Pape Demba Diop.

Allan Saint-Maximin fired in a second from the edge of area, but Santiago Hidalgo dragged Toulouse back into the match after Lens played themselves into trouble in defence.

Matthieu Udol turned in from close range to restore a two-goal cushion for Lens, who got a fourth from Adrien Thomasson in the second half before supporters flooded the pitch at full-time to celebrate a first appearance in the final since 1998.

"I'm already looking ahead to the final, because getting there without winning the cup isn't the reward that people deserve," said Sage.

"The run has been good, but I want to see it through to the end. Everyone here deserves it."