Marseille, who clinched a place in the UEFA Cup with a 0-0 Champions League draw with Atletico Madrid on Tuesday, lie second three points behind Lyon and would go first on goal difference with a win at Gerland.
Such a feat would be good news to all those tired of Lyon's supremacy and would give Marseille more to celebrate after their fan who was sentenced to jail in Spain was released on bail a few hours before Tuesday's game.
Santos Mirasierra, was sentenced to 3-1/2 years in prison last week after assaulting police officers during the team's first meeting in Madrid two months ago.
"He's a member of our family and we fought to have him back," Marseille chairman Pape Diouf told reporters. Mirasierra is now waiting for his appeal trial.
Lyon, the measure of all things in France for years, top the league table and have advanced to the last 16 of the Champions League but have looked vulnerable lately.
Their 2-1 defeat at strugglers Nantes last weekend left them with just one point from their last three Ligue 1 outings and under threat from Marseille, chasing their first trophy since their 1993 Champions League triumph.
Lyon coach Claude Puel has plenty of worries with defenders Francois Clerc, Anthony Reveillere and Mathieu Bodmer all out injured but can at least count on France striker Karim Benzema, fit again after nursing a sore thigh muscle.
Not only Marseille dream of ending Lyon's reign. Paris St Germain, waking up after fighting against relegation last season, were in fifth place five points back before visiting lowly Auxerre on Saturday.
PSG, who reinforced themselves this summer by signing former France midfielders Claude Makelele and Ludovic Giuly, know they can rely on young striker Guillaume Hoarau, the league's top scorer with 10 goals.
"Can we target the title?. I don't know but we can certainly dream of it," PSG defender Sammy Traore told reporters.
