Lens ended a difficult campaign on a high after an early Pablo Chavarria goal earned them a 1-0 home victory over Nantes.
Liverpool give U21s more game time than Premier League rivals but top flight lags behind Europe.
Nice confirmed their Ligue 1 status, but they did it the hard way, coming from behind to beat bottom club Lens.
Marseille kept their hopes of Champions League qualification alive after a late comeback saw them beat Monaco 2-1.
A stoppage-time winner from Anthony Mounier was enough to give Montpellier a 1-0 win over 10-man Lens.
Lens' relegation from Ligue 1 was sealed on Sunday afternoon as they slumped to a 3-1 loss at derby rivals Lille.