Confidence was high after last Sunday’s 2-1 home win against French champion Paris Saint-Germain, and goals from midfielder Clement Grenier in the first half and powerful centre forward M’Baye Niang soon after the break made it nine points from three games.
Grenier, a former France international whose career has been blighted by injuries, expertly chested down the ball before advancing into the penalty area and slotting in an angled shot in the 16th minute. Niang followed up his fine effort against PSG by sweeping in from close range in the 54th.
PSG hosted Toulouse later Sunday.
Monaco, meanwhile, is still seeking its first win after drawing 2-2 at home to Nimes.
New signings Wissam Ben Yedder and Islam Slimani scored to put Monaco 2-0 up at halftime.
But after Brazilian defender Jemerson’s 55th-minute sending off, Nimes hit back through midfielder Romain Philippoteaux and 18-year-old forward Kevin Denkey — with his first touch after coming off the bench. Algerian midfielder Zinedine Ferhat set both goals up.
Lyon can move back top on goal difference with a win at Montpellier on Tuesday.