Frustrated Marseille supporters made their feelings at the team's poor form clear by defacing some of the walls at the club's training ground with insults aimed at interim coach Jose Anigo and president Vincent Labrune.
But the hosts served up a timely response as Andre Ayew's hat-trick boosted their flagging European hopes, while Ajaccio are now 15 points from safety with just six games remaining to preserve their top-flight status.
Ayew calmed Anigo's nerves with the opener after just three minutes, lobbing Guillermo Ochoa in the visitors' goal in an otherwise uneventful first half on the field.
A notable minority of the home fans still voiced their disapproval at the half-time whistle, clearly unimpressed by the narrow lead held by their side.
Ayew's second of the night, a well-placed header on the hour mark, looked to have calmed the tension, only for Gadji Tallo to hit back for Ajaccio within two minutes despite replays showing him to have been offside.
A well-worked free-kick led to Ayew's third in the 76th minute, the striker taking his league goals tally to five for the campaign as Marseille moved to within six points of fourth-placed Saint-Etienne.
