Marseille escaped with a 1-1 draw at Rennes on Saturday night to end a run of six successive defeats in all competitions.
Despite trailing to a goal from Nelson Oliveira, OM hit back soon after with a Jordan Ayew strike.
And they held on to that point by the skin of their teeth as Oliveira saw a second-half penalty saved by Steve Mandanda before the goalkeeper made another crucial intervention in stoppage time.
OM coach Elie Baup had said before the match he was not too disheartened by his side's poor run, but he may have been reconsidering that opinion when they fell behind after just nine minutes at the Stade de la Route de Lorient.
Jonathan Pitroipa's cross was poorly dealt with by defender Jeremy Morel and the clearance fell kindly for Oliveira, who responded with 20-yard bullet into the top corner.
However, the visitors were back on level terms six minutes later thanks to Ayew, who got on the end of a pass from Alaixys Romao to stab home from close range.
That goal gave Marseille a renewed sense of confidence and they could have gone in front on the half-hour but Florian Thauvin's left-footed volley was a fraction too high, kissing the crossbar on its way over.
Rennes came back fighting in the second half and Oliveira also fired inches over the target as they looked to regain the advantage.
And they were handed the perfect opportunity to do so after 74 minutes when Kassim Abdallah tripped Foued Kadir in the area.
Oliveira took responsibility for the resulting spot-kick but his low strike was kept out by Mandanda.
And the OM keeper came to the rescue again three minutes into stoppage time, denying Oliveira once more as the Portuguese forward tried to force a winner from close range.