Girouds header clinches Lilles turnaround win on the road against Marseille
After their midweek departure from the UEFA Europa League, Lille now focus entirely on clinching a top-four position this campaign, facing direct rivals Marseille in this key fixture.
Starting five points adrift of the Phocéens, the away side created the games opening clear chance as the ball found Thomas Meunier near the penalty areas edge, his fierce drive sailing just past the left upright.
The hosts suffered an early setback around the 15-minute mark when Mason Greenwood was fouled by Calvin Verdonk during a counter-attack break, leading to his withdrawal shortly after due to the challenge's effects.
However, Greenwoods substitute, Ethan Nwaneri, would prove influential as the first half progressed.
The action ignited in the 43rd minute as Igor Paixao surged down the left wing to the goal line, his pull-back converted coolly into the bottom corner by the on-loan Arsenal youngster.
Pierre-Emerick Aubameyang nearly extended Marseilles advantage before the interval, charging towards goal before colliding with Berke Ozer, which forced the Lille goalkeeper off with a head knock.
Lille responded brilliantly at the start of the second period, drawing level just four minutes in. Meunier delivered a low pass across the box, and with the Marseille backline unable to clear, the Belgian reacted quickly to smash home his debut Ligue 1 strike this season.
Les Dogues thought they had taken the lead soon after as Matias Fernandez-Pardo raced clear and slotted neatly, but the goal was disallowed for offside.
Marseille found it tough to generate openings post-equaliser, not threatening again until the 73rd minute when Amine Gouiri unleashed a strong shot from outside the area that missed the left post narrowly.
In the end, Lille dominated the closing stages, and after Hakon Haraldsson was thwarted by Geronimo Rulli from close range, the visitors reward came with under five minutes left.
Meunier, fresh from his goal, switched to creator, delivering a precise cross met by the forehead of experienced forward Olivier Giroud, who powered in his 10th strike of the term.
Lille managed the final moments comfortably, handing Marseille a loss that exposes their third-place standing before the international hiatus. Under Bruno Genesio, the visitors now trail by just two points in fifth, pushing for another European qualification.