Lens need a miracle if they are to avoid an immediate return to Ligue 2 after succumbing to a 3-0 loss at the hands of high-flying Monaco.
Antoine Kombouare's side are 12 points off Reims, Lorient and Caen with four games remaining but would need to significantly improve their goal-difference of -26 to stay up.
Much of the damage was done by half-time at the Stade de la Licorne on Sunday as Yannick Ferreira-Carrasco and Anthony Martial put the visitors in cruise control.
Showing little sign of fatigue form their UEFA Champions League exertions, Monaco's win was wrapped up by Bernardo Silva as they moved back into third place in Ligue 1.
Leonardo Jardim's side remain six points off leading pair Lyon and Paris Saint-Germain, after the latter joined the defending champions on 68 points at the summit.
Only goal difference separates the sides, ahead of PSG's game in hand against second-bottom Metz on Tuesday, as Hubert Fournier's men claimed a 4-2 win at Reims.
After a goal-packed opening 20 minutes, the visitors led 3-1 following goals from Corentin Tolisso, Alexandre Lacazette and Clinton N'Jie.
Both sides claimed further goals late on in a thrilling game at the Stade Auguste-Delaune while Saint-Etienne needed just the one goal to get past Montpellier.
Max Gradel scored for a second game running to ensure a 1-0 win and send his side fourth, having seen Marseille's difficulties continue with defeat to Lorient on Friday.