Marseille are now without a win in three matches following a 2-1 loss at home to Angers, which has lifted the visitors up to fifth place in the Ligue 1 table.
The game was played in front of a depleted crowd after Marseille were hit with a partial stadium ban and they were stunned into silence when Angers took a 38th-minute lead.
Newcastle United loanee Remy Cabella was penalised for a foul inside the area and Thomas Mangani stepped up to dispatch the resulting spot kick.
Michel threw on Lucas Silva at the break in an attempt to change his side's fortunes and they came close on a number of occasions shortly after the interval.
First, Silva flashed a shot wide before Michy Batshuayi and then Bouna Sarr were both denied by Ludovic Butelle saves.
With 69 minutes on the clock, Romain Thomas headed home Mangani's free kick to double the away side's advantage.
Ferebory Dore handed Marseille a lifeline when he made a foul inside the area, allowing Batshuayi to halve the deficit from 12 yards, but Marseille were unable to find an equaliser in the dying stages of the game.