Olivier Giroud grabbed his 14th goal of the season to leave Rene Girard's men to within three points of leaders PSG, whilst also handing OL their seventh defeat of the campaignMontpellier HSC reversed their recent run of bad form by beating an injury-hit Olympique Lyonnais 1-0 in their Ligue 1 encounter at Stade de la Mosson.
La Paillade were the better of the two sides in a competitive game, and could've taken the lead after 30 minutes had Remy Cabella's effort not hit the woodwork. Perseverance paid off for Montpellier who broke the deadlock after the hour through Olivier Giroud.
Lyon failed to seriously trouble the hosts' back-line, and could only muster sporadic chances, though Alexandre Lacazette should have done better with a late opportunity afforded to him.
Remi Garde endured a major defensive crisis heading into this match, with no first or second choice defenders available. Anthony Reveilliere, Dejan Lovren and Cris were all injured, Mohamadou Dabo suspended, and John Mensah, Sidy Kone and Bakary Kone at the Africa Cup of Nations.
With Guieda Fofana slotting in at right-back, and Garde relying on the unusual partnership of Samuel Umtiti and midfielder Maxime Gonalons in central defence, Lyon could be forgiven for looking a little rough around the edges in the early stages on the south coast.
Rene Girard's high-flying outfit were the better of the sides, creating much of the early chances, but top scorer Olivier Giroud failed to manoeuvre a way past the visitors' makeshift defence.
It wasn't until the half-hour mark that either side fashioned the first gilt-edged chance, and when it did come, it really should've been 1-0 to the hosts. Remy Cabella, latching on to Giroud's header, smashed a half-volley which cannoned off the post as Hugo Lloris scrambled.
Montpellier pressured their visitors, and la Paillade again spurned another decent chance. John Utaka raced down on the left-flank, picking out Giroud who fired an audacious overhead kick wayward. The pair linked up again, but this time he was thwarted by Lloris as the hosts finished the half strongly.
Les Gones' were once again uncertain at the back with Montpellier unrelenting in their attacking play. Giroud raced past his marker, with Gueida Fofana pulling out a last-minute stop to deny Geoffrey Dernis.
However, by this point, Lyon's luck had run out and the home side finally got their goal. Dernis' long ball found Giroud, who beat the offside trap and slid an effort past Hugo Lloris from a tight angle after the hour mark to make it 14 goals in Ligue 1 this season for the striker.
Substitute Alexandre Lacazette wasted arguably Lyon's best chance in front of goal late on, taking too long to trigger his shot away, as a resolute defence stood firm. Marco Estrada and Karim Ait-Fana also were profligate for the hosts, who should've scored more on the day.
Neither side could produce any late drama, as Remi Garde's visitors were handed their sixth defeat on the road this season and seventh overall as their title challenge took a considerable dent. Rene Girard's men remain three points off the top.
Montpellier travel to Nice on matchday 21, as Lyon host Dijon. Both sides have Coupe de France round of 16 commitments next week against lower-league outfits.