Marseille have slumped to a surprise defeat in their opening Ligue 1 game of the season at home to Caen.
OM, in front of a busy Stade Veldrome, almost fell behind in the third minute as Andy Delort's shot was saved by Steve Mandanda.
Michy Batshuayi then fired wide for Les Olympiens, but Caen continued to press in the early stages when another Delort effort, from Dennis Appiah's cross, was met by another Mandanda stop.
Marseille came close to going ahead against the run of play when Benjamin Mendy rattled the woodwork.
However, it was Caen who made the first breakthrough as Delort fired his shot into the top corner of Mandanda's net.
Romain Alessandrini tried to give Marseille a first-half equaliser with a shot from distance, but couldn't hit the target.
Marcelo Bielsa reshuffled his pack with the introduction of Lucas Ocampos at half time and the forward almost got his team level as he shot narrowly wide.
The Argentine coach also threw on Georges-Kevin Nkoudou and Bouna Sarr in a desperate attempt to inspire a comeback.
However, despite Sarr bringing a save out of Remi Vercoutre, Caen were able to hold on for victory.