The club are still looking for a first trophy since 2003 after capitulating in Saturday's league cup final clash against PSG.
The principality club are still looking for a first trophy since 2003 after capitulating in Saturday's clash with Paris Saint-Germain in Lyon, losing 4-1.
But they are still top of Ligue 1 -- albeit with PSG breathing hard down their necks -- and made light work of visiting Lille at a sparse Louis II Stadium despite fielding a weakened side.
Striker Radamel Falcao and starlets Kylian Mbappe and Tiemoue Bakayoko were all named on the bench.
Monaco took the lead in the 35th minute when striker and captain-for-the-night Germain rifled high into the roof of the net and five minutes later Lille were in deeper trouble when Carlens Arcus was sent off for hauling down Jorge as the Brazilian had a run at goal.
The prolific Monaco -- who have hit 87 goals in the French league already this season -- made it 2-0 against fellow Ligue 1 side Lille just before the break when Germain struck again, this time from close range.
Lille pulled a consolation goal back through Anwar El Ghazi deep into stoppage time.
Monaco join Guingamp, French Cup winners in 2009 and 2014, in the last four after they squeezed past fourth-tier minnows Frejus Saint-Raphael 1-0.
On Wednesday PSG, eyeing a third consecutive clean sweep of the domestic honours in France, take on third-tier Avranches away. Angers host Bordeaux.