Lyon sink further at Montpellier
Lyon midfielder Jordan Ferri (R) vies for the ball with Montpellier forward Djamel Bakar during the French L1 match at the Mosson stadium in Montpellier, southern France on October 6, 2013
Remi Garde's side have won just one of their last 11 matches in all competitions and struggled from the outset against Montpellier, who are traditionally strong at home.
Club president Jean-Michel Aulas admitted that the team are in "crisis" but blamed a string of injuries among their defence for their poor form.
"There is always a crisis when there is such a heavy defeat and a systematic failure to win," he said.
"We're going to deal with this crisis amongst ourselves and above all to find the origin of the epidemic of injuries particularly in defence with seven or eight players affected."
He added: "We have to support the coach, that's why I'm here. This defeat is the result of injuries among the players and we have to find the cause of this."
Jean Fernandez's Montpellier could largely thank the double act of strikers Victor Hugo Montano and Anthony Mounier for their success.
The hosts missed a big chance to take the lead off a Remy Cabella header after 13 minutes but Montano and Mounier made up for the error by scoring a double each.
Colombian striker Montano scored his third goal of the season after 16 minutes and just before the break Mounier added a second when he picked up a header following a Cabella corner.
Lyon missed a string of chances noteably by striker Bafetimbi Gomis, but reduced the deficit just after the break when Alexandre Lacazette found the net.
But they crumbled faced with a superb Cabella-Montano partnership.
Cabella converted a penalty after 59 minutes following a foul on Montano and scored a second seven minutes later. He then set up Montano (68) for his second off a header.
Lyon, who won the last of their seven-consecutive titles in 2008, are four points above the drop zone.
Monaco went three points clear at the top of Ligue 1 on Saturday after a late Lucas Ocampos winner gave them a priceless 2-1 victory over Saint-Etienne at the Louis II stadium.
Substitute Ocampos was the star for Claudio Ranieri's Cote d'Azur outfit, when he latched onto a low cross from the right and pounced inside a crowded penalty box to shoot past Stephane Rufier with just three minutes remaining.
The win keeps Monaco unbeaten with six victories from nine matches and lifts them three points clear of Paris Saint-Germain who travel to arch- rivals Marseille on Sunday.