Eight points clear at the top less than two months ago, the champions are now level on points with second-placed Montpellier, who host Auxerre on Saturday.
Bordeaux looked below par in a 1-1 home draw with Montpellier last Sunday and frustrated their supporters even more when they lost 2-1 to Auxerre at their Chaban-Delmas stadium on Wednesday.
"We cannot afford to pick up just one point from two home games," Bordeaux defender Mathieu Chalme told reporters after the game. "For a team fighting for the title, it is simply not good enough."
FEATURE:Bordeaux's Blanc face past and present with Montpellier
Bordeaux, who visit Monaco on Saturday, still have a game in hand but it is now obvious that they have dangerous rivals and will have to work to defend their crown.
Surprise package Montpellier are not the only team to have moved within reach. Auxerre are in third place, one point back, and fourth-placed Olympique Lyon are two points off the pace.
Lyon, welcoming neighbours St Etienne on Saturday, are full of confidence after taking 20 points from a maximum 24 this year and knocking out Real Madrid to reach the quarter-finals of the Champions League.
"Bordeaux losing is good news to us but we must concentrate on what we need to do," Brazilian defender Cris, the Lyon captain, told reporters. "Bordeaux are still the leaders and even if we are looking good, we have not won anything yet."
Bordeaux also need to watch out for fifth-placed Olympique Marseille, who are only three points adrift and have a game in hand.
Marseille, who have not won a title since their Champions League triumph in 1993, visit Toulouse on Sunday.
