Lyon missed the creative spark of injured playmaker Yoann Gourcuff as it dropped its first points of its new campaign with a 1-1 draw at modest Evian.
Lyon had won its two opening games but fluffed its lines as only a Michel Bastos equaliser 16 minutes from time saved its blushes after Cedric Barbosa had given Evian the lead on 57 minutes with a neat volley.
Bastos had only minutes earlier replaced Lisandro when he pounced with a direct free kick which flew through a poorly organised wall.
Wins over Rennes and Troyes had taken Lyon to the summit on goal difference after thrashing Troyes 4-1 but Gourcuff sustained a knee ligament injury in that game and he faces three months out of action.
Lyon, champion seven years in a row between 2002 and 2008, finished a disappointing fourth last term and has brought in only one new player - Serbian defender Milan Bisevac, from Paris Saint-Germain - in the transfer window.
After the two dropped points, Lyon - who earlier announced the six million euros transfer of defender Aly Cissokho to Valencia - could now be overhauled at the weekend by Marseille, Bastia and Bordeaux.
Marseille, champion in 2010, faces reigning titleholder Montpellier with the latter still yet to win having drawn with Toulouse and then lost at Lorient.
The champion has Chilean midfielder Marco Estrada out injured and defensive midfielder Jamel Saihi is suspended, but new signing Anthony Mounier could make his first league appearance for the club after missing the opening two matches due to a thigh problem.
Lille, the 2011 champion, and Paris Saint-Germain will hope to get on track with the former struggling to reach the UEFA Champions League group stage after losing to FC Copenhagen in their play-off tie on Tuesday. The northerners face a Saturday trip to Nice.
Qatari-backed PSG is already four points off the pace in Ligue 1 after behind held by first Lorient and then Ajaccio and will hope for its first win bonus at home to Bordeaux on Sunday.
PSG coach Carlo Ancelotti could hand a debut to Brazilian centre-back Thiago Silva, who is yet to feature after his 42-million-euro ($52.3 million) transfer from AC Milan.
French champion Paris Saint-Germain has reportedly commenced discussions with Wayne Rooney with a view to signing the want-away Manchester United striker.