Lyon and PSG do not play until Sunday, meaning Marseille and Bordeaux have a chance to jump to the summit for 24 hours at least - and it will be a surprise if either side fail to win on Saturday night.
OM, fresh from a 3-1 win over PSG last weekend and having secured their progress into the UEFA quarter-finals on Wednesday night at the expense of Ajax, are at home to fifth-bottom Nantes, who are winless in six games.
Les Girondins, meanwhile, travel to bottom side Le Havre, who appear doomed as they are 11 points adrift of safety with just 10 rounds of fixtures left.
Lyon welcome fourth-bottom Sochaux late on Sunday afternoon and, according to their defender Mathieu Bodmer, are still in the driving seat to claim their eighth successive title even though they have lost their last four matches in all competitions.